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1 



NORTH AMERICAN FAUNA 

No. 56 



REVISION 

OF THE NORTH AMERICAN 

GROUND SQUIRRELS 

With a Classification of the North American 
Sciuridae 



By 
ARTHUR H. HOWELL 

Senior Biologist 

Section of Wildlife Surveys, Division of Wildlife Research 

Bureau of Biological Survey 




^/V^L 



Issued by 

UNITED STATES DEPARTMENT OF AGRICULTURE 
BUREAU OF BIOLOGICAL SURVEY 

Washington, D. C. ApniL 1938 

For mU by xh» Sup«riDtend«ot of Docomenta, Washington, D. C- - -- - - - Wo* ^ ««"»t3 



PUBLICATIONS in the NORTH AMERICAN FAUNA SERIES 



Copies of the North American Fauna not out of print are for sale, at the prices named, 

by the Superintendent of Documents, Government Printing Office, Washington, D. C. 

Numbers marked with an asterisk [*] are out of print. 



*No. 1. Revision of the North American Pocket 
Mice. By 0. Habt Mebbiam. 
Pp. 36, pis. 4. 1889. 

*No. 2. Descriptions of Fourteen New Species 
and One Nevr Genus of North American Mam- 
mals. By C. Habt Mbbbum. 
Pp. 62, pis. 8, figs. 7. 1889. 

*No. 3. Results of a Biological Survey of the San 
Francisco Mountain Region and Desert of the 
Little Colorado, Arizona. By O. Habt Mebbiam 
and Leonhabd Stejnsgeb. 
Pp. 136, pis. 14, maps 6 (colored), Sgs. 2. 1800. 

*No. 4. Descriptions of Twenty-six New Species of 
North American Mammals. By O. Habt Meb- 
biam. 
Pp. 60, pis. 3, figs. 3. 1890. 

*No. 5. Results of a Biological Reeonnolssance of 
South-central Idaho. By C. Habt Mebbum and 
Leonhabd Stbimbgeb. Descriptions of a New 
Genus and Two New Species of North American 
Manunals. By C. Habt Mebbum. 

Pp. 132, pis. 4 (1 colored), figs. 4. 1891. 
No. 6. Not iaaued. 

*No. 7. The Death Valley Expedition: A Biological 
Survey of Parts of California, Nevada, Arizona 
and Utah. Part II: 1. Birds, by A. K. Fishke. 
2. Reptiles and Batrachlans, by Leonhabd Stbi- 
NEOEB. 3. Fishes, by Chables H. Qilbebt. 1. In- 
secfB, by O. V. RaET. 6. MoDusks, by K. E. C, 
Stb ABN8. S. Desert Trees and Shrubs, by. C . Habt 
Mebbum. 7. Desert Cactuses and Yuccas, by 
O. Habt Mebbiam. 8. List of Localities, by T. S. 
Palmeb. 
Pp. 402, pis. 16, maps 6, figs. 2. 1893. 

*No. 8. Monograptilc Revision of the Pocltet 

Gophers, Family Geomyi^ae (exclusive , of the 

species of Thomomys). By O..Eabi. Meseium. 

Pp. 258, pis. 20, figs. 71, maps 4 (qoi{ir&d)\ i^[ ,' ; 

No. 9. Xot iuued. 

*No. 10. Revision of the Shrews of the Amar&an 
Genera Blarina and Notiosorex. By C 'Ea&t 
Mebbum. The Long-tailed .Slwews of .thp East- 
em United States. By QiJ^iifT; s'. Miii^^l ir.. 
Synopsis of the American Stiir^wa of i<bc ^G^iAr 
Sorex. By O. Habt Mebbum. 
Pp. 124, pis. 12, figs. 3. 1895. 

*No. 11. Synopsis of the Weasels of North Amer- 
ica. By O. Habt Mebbum. 
Pp. 44, pis. 6, flgs. 16. 1896. 

*No. 12. The Genera and Subgenera of Toles and 
Lemmings. By Qebbit S. Milleb, Jr. 
Pp. 84, pis. 3, figs. 40. 1896. 

*No. 13. Revision of the North American Bats 
of the FamUy Tespertillonidae. By Qebbit S. 
MniEE, Jr. 
Pp. 140, pis. 3, figs. 40. 1897. 

*No. 14. Natural History- of the Tres Marias Is- 
lands, Mexico: General Account of the Islands 
with Reports on Mammals and Birds, by £. W. 

Nelson. Reptiles, by Leonhabd Stbjnegeb. Notes 
on Crustacea, by Maby J. Rathbun. Plants, b^ 
J. N. Rose. Bibliography, by E. W. Nkison. 
Pp. 97, pi. (map), figs. 2. 1899. 



*No. 15. Revision of the Jumping Mice of the 
Genus Zapus. By Edwabd A. Pbeble. 
Pp. 42, pi. 1, figs. 4. 1899. 

*No. 16. Results of a Biological Survey of Mount 
Shasta, California. By O. Habi Mebbiam. 
Pp. 179, pis. 6, figs. 46. 1899. 

*No. 17. Revision of American Voles ofthe Genus 
MIcrotus. By VERNdN Bailet. . 
Pp. 88, pis. 6, flgs, 17. 1900. 

*No. 18. Revision of the Pocket Mice of the 
Genus Perognathus, By Wiltbsd H. Osgood. 
Pp. 72, pis. 4 (Incl. 2 mops), flgs. 16. 1900. 

*No. 19. Results of a Biologic Reconnoissancci 
of the Yukon Region, ,G^eral Account of th^ 
Region. Annotated List of Mammals, by Wu/- 
FBED H. Osgood. Annotated List of Birds, by 

Loins B. Bishop. 
Pp. 100,pls.7(lncl. Imap). 1900. 

*No. 20. Revision of the Skunks of the Genus 
Chincha [Mephitis]. By Abthxtb H. Howeix. 
Pp. 62, pis. 8. 1901. 

*No. 21. Natural History of the Queen Charlotte 
Islands, British Columbia; and Natural History 
of the Cook Inlet Region, Alaska. By Wiltbed 
H. Osgood. 
Pp. 87, pis. 7 (incl. 1 map), fig. (map). 1901. 

*No. 22. A Biological Investigation of the Hudson 
Bay Region. By Edwabd A. Pbeble. 
Pp. 140, Ids. 14 (incl. 1 map). 1902. 

*No. 23. Index Generum Mammalium: A List 
of the Genera and Families of Mammals* By 

T. S. Palmeb. 
Pp.984. 1904. 

*No..2,4>. A Biol^^cal Reconnaissance of the Base 
of tM .^agkH Peninsula. By Wiltbed H. Osgood. 
' Pp.a5i.p!9,7(incl. 2maps). 1904. 

>*^o. 25. Biological Survey of Texas: life Zones* 
'. siili Characteristic Species of Mammals, Birdsi 
Reptiles, and Plants. By Vebnon Bailbt. 
Pp. 2c'?3,.pls. J6 (Ind. 6 maps), figs. 24 (ind. 16 maps) . 

■ im^ ' >/ ".. 

'"'No.'26.'Rev)fy4dn of the Skunks of the Genus 
SpUogale. By Abthub H. Howell. 
Pp. 65, pis. 10 (Incl. 1 map), 1906. 

No. 27. A Biological Investigation of the Atha- 
basIm-Mackenzie Region. By Edwabd A. Pbeble. 
Pp. 574, pis. 25 (incl. 4 maps), figs. 16. 1908. 

*No. 28. Revision of the Mice of the American 
Genus Peromyscus. By Wiltbed H. Osgood. 
Pp. 285, pis. 8 (incl. 1 map), figs, 12 (maps). 1909. 

*No. 29. The Rabbits of North America. By E. 

W. Nelson. 
Pp. 314, pis. 13, figs. 19 (ind. 16 maps). 1909. 

*No. 80. Biological Investigations in Alaska and 
Yukon Territory: 1. East-central Alaslia; 2i 
OgUvIe Range, Yukon; 3. Macmlllan River 
Yukon. By Wilfbkd H. Osgood. 
Pp. 96, pis. 6 (1 map), figs. 2 (maps). 1909. 

(.Continued on page S of cover) 



NORTH AMERICAN FAUNA 



No. 56 



issued -=^^^^^»L ^y '^* 
UNITED STATES DEPARTMENT OF AGRICULTURE 

BUREAU OF BIOLOGICAL SURVEY 



Washington, D. C. 



April 1938 



REVISION OF THE NORTH AMERICAN GROUND 
SQUIRRELS, WITH A CLASSIFICATION OF THE 
NORTH AMERICAN SCIURIDAE 

By Arthur H. Howell, senior biologist, Section of Wildlife Surveys 
Division of Wildlife Research 



CONTENTS 



Introduction .- 1 

Geographic distribution of the ground 

squirrels.- 2 

Habits and economic relations 4 

Townsend's ground squirrel and related 

races 5 

Snake Valley ground squirrel 6 

Washington ground squirrel 7 

Eichardson's ground squirrel 8 

Wyoming ground squirrel 10 

Uinta ground squirrel 10 

Belding's ground squirrel... 11 

Oregon ground squirrel. 12 

Columbian ground squirrel and related 

races... 13 

Parry's ground squirrel and related races... 16 

Yukon Valley ground squirrel. 17 

Striped ground squirrels 18 

Mexican ground squirrels 20 

Spotted ground squirrels 20 

Perote ground squirrel 21 

Franklin's ground squirrel 21 

Rock squirrels 22 

California ground squirrel and related 

races 23 

Douglas's ground squirrel 27 

Ring-tailed and Goldman's ground squir- 
rels 28 

Lesser tropical ground squirrel 29 

Antelope ground squirrels 29 

Mohave ground squirrel 30 

Round-tailed ground squirrels. 30 

Mantled ground squirrels 31 



Page 
Classification of the North American Sciiui- 

dae 34 

Genus Marmota: Marmots 37 

Genus CynoTnys; Prairie dogs. — 38 

Genus Citellm: Ground squirrels 39 

Genus Tamia*; Eastern chipmunks 46 

Genus Eulamias: Western chipmunks 47 

Genus Sciurus: Tree squirrels - 48 

Genus Tamiasciurus: Red squirrels 61 

Genus Microsciurus: Pygmy squirrels 51 

Genus Syntheosciurus: Pygmy squirrels 52 

Genus Glaucomys: Flying squirrels 62 

Revision of the genus Citellus S3 

History and nomenclature... — 53 

Generic and subgeneric names 53 

Subgenus Citellus Oken 59 

Citellus townsendii group 60 

Citellus uashingtoni group 69 

Cilettus Tichardsonii group 73 

Citellus panyii group 85 

Subgenus /c/idoTny* Allen 106 

Cilelltis tridecemlineatus group 106 

CUellus spilosoma group — 122 

Subgenus Poliocitellus, nobis. 133 

Subgenus Otospermcphilus Brandt 135 

Subgenus NotocUellus, nobis 162 

Subgenus Ammospermophilus Merriam 166 

Subgenus Xerospermophilus Merriam 183 

Subgenus Callospermophilus Merriam 190 

Fossil species .-- - 214 

Bibliography 217 

Index 247 



INTRODUCTION 

The ground squirrels of North America now comprise 97 distinct 
forms in 31 species. These were arranged in the check list of Miller 
(1924)^ under the four generic names Citellus, Otospermophilus, 
Callospermophilus, and AmmosperTnophilus. For many years there 
has been considerable uncertainty as to the relationships of the 
genera, subgenera, and species. As a result of the present study, the 

' Citations in parentheses refer to the Bibliography, p. 217. 

154970—38 1 1 

.UPCRINT Ell DENT OF DOGUWtiS. 



4 r\f\f\ 



2 NORTH AMERICAN FAUNA [No. 56 

ground squirrels are now grouped under a single genus, Gitelltos, 
"which is divided into eight subgenera. 

The material on which the revision is based is principally con- 
tained in the collection of the United States National Museum, in- 
cluding that of the Bureau of Biological Survey. In addition, large 
series of specimens have been borrowed from several of the larger 
museums in the United States and Canada.^ Altogether 11,724 speci- 
mens have been examined and identified. 

One of the early bulletins of the Bureau — that on the Prairie 
Ground Squirrels, or Spermophiles, of the Mississippi Valley 
(Bailey, 1893) — ^treated of the habits of five of the more important 
species. Other writers have published reports on the habits and 
economic relationships of various other species, notably that by 
Grinnell and Dixon (1918) on the Natural History of the Ground 
Squirrels of California. 

The group as a whole has not been revised for many years and 
there has been considerable uncertainty as to the relationships and 
the proper allocation of many of the species. This publication pre- 
sents the results of a study of the systematic relationsliips and geo- 
graphic distribution of the American members of the genus, with a 
summary of the known facts of their life history, together with a 
critical study of the systematic classification of all the North Ameri- 
can members of the Sciuridae, the family of which the ground 
squirrels are members. 

The colored plates (1 to 11) here reproduced were made about 40 
years ago for the Biological Survey from drawings by Ernest E. 
Thompson, now known as Ernest Thompson Seton, and were printed 
in expectation that a report on the ground squirrels would soon be 
issued ; although the revision for which the plates were made has been 
long delayed, it is now possible to present the illustrations in this 
volume. 

GEOGRAPHIC DISTRIBUTION OF THE GROUND SQUIRRELS 

Ground squirrels of the genus CiteUus are widely distributed, both 
in North America and in Eurasia. The type species C. citelhis, 
ranges from Bohemia eastward through the Union of Soviet-Social- 
ist Republics into Asia, and the genus, represented in Eurasia by 
20 or more described species, occupies parts of southeastern Europe 
and central Asia eastward into Siberia, Most of the Eurasian 
forms appear to be quite distinct from those of the New World, but 



2 For the loan of material used in this study the author extends thanks to the owners 
and custodians, as follows : R. M. Anderson, National Museum of Canada ; F. Kermode, 
Provincial Museum of British Columbia ; Glover M. Allen, Museum of Comparative Zoology ; 
Albert H. Wright, Cornell University ; H. B. Anthony and G. G. Goodwin, American 
Museum of Natural History ; Witmer Stone and Wharton Huber, Academy of Natural Sciences 
of Philadelphia; Earl L. Poole, Reading (Pa.) Public Museum; B. P. Bole, Jr., Cleveland 
(Ohio) Museum of Natural History; L. R. Dice, University of Michigan Museum of Zjology; 
William L. Engcls, University of Notre Dame ; W. H. Osgood, Field Museum of Natural His- 
tory ; W. H. Over, South Dakota Biological Sui"vey ; Myron H. Swenk, University of Nebraska ; 
C. D. Bunker, Kansas University Museum of Birds and Mammals ; Frederick W. Miller, 
Colorado Museum of Natural History ; Ernest Morris, State Historical Society of Colorado, 
Denver ; R. F. Crawford, State College of New Mexico ; William H. Spaulding, Montana 
State College ; J. S. Stanford, Utah State Agricultural College ; Vasco M. Tanner, Brigham 
Young University ; Joseph Grinnell and E. R. Hall, Museum of Vertebrate Zoology ; Loye 
H. Miller, Los Angeles Museum ; L. M. Huey, San Diego Society of Natural History ; 
Chester Stock, California Institute of Technology ; J. H. Fleming, Toronto, Ontario ; 
C. B. Garrett, Cranbrook, British Columbia ; P. F. Hickie, Lansing, Mich. ; S. G. Jewett, 
Portland, Oreg. ; E. T. Seton, Santa Fe, N. Mex. ; William T. Shaw, Fresno, Calif. ; Dayton 
Stoner, Albany, N. Y. ; and Edward R. Warren, CJolorado Springs, (iolo. 



laSS] REVISION OF THE GROUND SQUIRRELS 3 

those from eastern Siberia — G. huxtoni and C. stejnegeri — are closely 
related to the Alaskan species C. parryii. 

The North American ground squirrels occupy a large part of the 
continent, from the Arctic coast of Alaska and Canada south to 
(xuerrero and the valley of Mexico. Being inhabitants chiefly of 
prairies and open mountain slopes, they are absent from the forested 
regions of the eastern parts of both Canada and the United States. 
The large ground squirrels of the Barren Grounds {G. parryii and 
its relatives) range from the shores of Hudson Bay westward to 
the coast of Bering Sea and are found also in eastern Siberia and 
on St. Lawrence Island; the striped ground squirrels of the Missis- 
sippi Valley {G. tridecemlineatus) extend eastward to Michigan 
and Ohio; the gray ground squirrel of the prairies {G. franklimi) 
reaches Indiana in its eastward range, and a colony introduced into 
New Jersey TO years ago still survives there. Practically the en- 
tire area of western North America, with the exception of the coast 
region of Washington and a large part of British Columbia, is oc- 
cupied by one or more species of ground squirrel. 

In the United States, ground squirrels are so abundant as to be 
highly destructive to agricultural crops. Their importance as fac- 
tors limiting the profits of the farmer has long been recognized, and 
from its early days the Biological Survey has been called upon to 
direct extensive control campaigns in many parts of the West. 



North American Fauna No. 56 

United States Department of Agriculture 

"Revision of the North American Ground Squirrels" 



CORRECTION SLIP-May Be Pasted at Foot of Page 3 

Actual date of publication, May 18, 1938 



Page 41, line 8 from end: For ^2, read ^. 

Page 119, line 1: For county spelling, read Moffat. 

Page 146, line 6 from end: For blank space in parentheses, insert 41fl- 

54V-59 5'''^ ^°'^' P^'"^"t^etical measurements insert dMh, to read 

Page 162, last line of section preceding Notocitellus : For 11, read 1 (San Pablo 
Page 185, line 12: For 34.3, read 34.9 (skull length). 



J. 154970—38. 



HABITS AND ECONOMIC RELATIONS 

The ground squirrels of North America differ from the tree squir- 
rels in their habit of living in burrows and most of them become 
dormant for periods of varying extent, in some cases even more than 
half the year. During the periods of estivation and hibernation 
there is a decided drop in temperature, the respiration and blood 
circulation are reduced to a minimum, the body becomes rigid, and 
the fat accumulated during the active period is practically all con- 
sumed. Wlien the animals emerge early in spring they feed spar- 
ingly at first on green vegetation and bulbs of wild plants or upon 
newly planted grain, if such is at hand. During the breeding season, 
wliich follows shortly after emergence from hibernation, the desire 
for green food increases and the squirrels feed on growing grain, 
alfalfa, wild herbs, and other succulent plants. Early in summer, 
as the season of estivation approaches, they turn their attention 
largely to the seeds of wild plants or to ripening grain ; after feed- 
ing for a few weeks on such nutritious food they become excessively 
fat, and are ready to enter on their long sleep. 

The fondness of certain of the ground squirrels for cultivated 
grain coupled with their ability to increase rapidly under favorable 
conditions, has made them one of the most serious pests with which 
the farmer has to contend. In addition to destroying immense 
quantities of grain and alfalfa, some species are destructive to cul- 
tivated fruits and nuts. 

The burrowing of ground squirrels on steep slopes frequently is 
the initiating cause of soil erosion, which at times becomes serious. 
Grinnell and Dixon (1918, p. 608), write of the burrows of the Cali- 
fornia ground squirrels as follows: 

■■' * * their burrows are frequently the cause of much destructive erosion 
on hillsides during heavy rainstorms. Numerous small landslides have been 
noted on steep hillsides on the campus at Berkeley, that were plainly caused 
by the presence of squirrel burrows which had concentrated and conducted the 
water in narrow channels instead of permitting it to spread out and soak in 
or run off in the natural way. 

Ground squirrel burrows are often a serious menace to the safety 
of irrigation systems. Birdseye (1912, p. 13) tells of a serious 
washout caused by irrigation water escaj)ing through a Columbian 
ground squirrel's burrow located in an orchard on the bench above. 
Lantz (1918, p. 14) cites the destruction of 6 acres of alfalfa caused 
by the burrowing of a California ground squirrel into an irrigation 
embankment. 

An additional count against certain of the ground squirrels is 
based on the part they play in the dissemination of diseases often 
fatal to man, as is the case with the Columbian ground squirrel in 
the spread of spotted fever, the California, Oregon, Uinta, Colum- 
bian, and Eichardson's ground squirrels in the spread of bubonic 
plague, and the California ground squirrel and the Utah rock squirrel 
in the spread of tularemia. 



1938] REVISION OF THE GROUND SQUIRRELS 5 

The species tliat live on deserts or in mountainous sections are of 
little economic importance, since they rarely come in contact with 
agricultural operations. This is true of mantled ground squirrels 
(subgenus Callospermophilus), antelope ground squirrels (subgenus 
Ammospermophilus) , round-tailed ground squirrels (subgenus 
Xerospermophilus) ^ and spotted ground squirrels {Citellus spilo- 
soma). 

The most serious damage to man's interests is occasioned by vari- 
ous species of the typical subgenus {Citellus) and by the rock squir- 
rels of the subgenus Otospermophilus. Franklin's ground squirrel 
{C. franklinii) and strij)ed ground squirrels {G. tridecemlineatus 
and G. mexicanus) are accounted pests in some sections by reason 
of their destruction of newly planted corn and garden vegetables, 
but this damage is in part balanced by their destruction of injuri- 
ous insects. 

The species that occasion the greatest damage to crops of grain, 
and against which extensive control operations have been necessary, 
are the Columbian ground squirrel (G. colu7nhianus) , Richardson's 
and Wyoming ground squirrels {G. richardsonii richardsonii and 
G. r. elegans)^ Oregon ground squirrel {G. heldingl oregGnus), 
Townsend's ground squirrel {G. townsendii), Washington ground 
squirrel {G. w ashing t oni) ^ and Douglas's and California ground 
squirrels {G. heecheyi subspp.). 

Detailed accounts of habits of various species follow. 

TOWNSEND'S GROUND SQUIRREL AND RELATED RACES =* 

General hahits. — Townsend's ground squirrel and related races 
{Gitellus townsendii subspp.) (pi. 1) inliabit dry, sandy, sagebrush 
valleys and to a lesser extent juniper-covered ridges among lava 
rocks. They live in dense colonies, digging their burrows under 
the sagebrush or sometimes out in the open. A burrow dug out by 
W. P. Taylor, in Humboldt County, Nev., was found to be about 30 
feet in length, but only about 8 inches below the surface. Of this, 
Taylor (1911, p. 218) writes: 

A nest was found in a large spherical cavity, so arranged that water conld 
not have gotten into it. Fine straws made np the bulk of it, though white 
cotton twine had been very largely used to bind the straws loosely together. 
A couple of rags, a bit of rabbit fur, some wool, and a down feather were 
also incorporated into the nest. Apparently the burrows intercommunicate. 

T. H. Scheffer excavated a burrow of the subspecies G. t. town- 
sendii at Kennewick, Wash., which had been treated previously 
with carbon bisulphide. The mother squirrel and seven young were 
found strung along the course of the burrow two of the latter in 
the nest. Scheffer (in manuscript) describes the burrow as follows: 

The runway descended rather steeply from the entrance, reaching a depth 
of 51^ feet at distance of 11 feet along the slope. From this point a branch 
ran downward to the right, for about 3 feet and ended in the nest chamber. 
Continuing slightly downgrade to a depth of 6 feet and a distance of 14 feet 
from the entrance, the main tunnel turned abruptly upward at an angle of 
about 70 degrees and reached the surface in a partly obstructed entrance 12 
feet from the point where excavation was begun. From the place of this up- 
ward turn the main tunnel had been opened up 5 or 6 feet farther into looser 

*" Formerly known as Citellus vkAUs subspp. For explanation of change of name see 
p. 62. 



6 



NORTH AMERICAN FAUNA [No. 56 



earth from an old badger digging. Tliis material was slightly damp as a 
result of moisture penetrating through soil worked over by the badger long 
ago. 

The nest chamber was about 6V2 inches in most dimensions and was located 
just beneath the consolidated stratum, its roof hollowed out in the latter. It 
was filled with a perfectly dry nest consisting of fine, grass partly broken and 
shredded. The two young found suffocated there were concealed in the nesting 
materials. 

Like other species of their tribe, these ground squirrels hibernate 
during a good part of the year — from July to the following Febru- 
ary. A single individual was seen at Blalock, Oreg., on February 1, 
1926; Scheffer found the squirrels out in numbers at Kennewick, 
Wash., the last week in January ; and R. Scott Zimmerman reports 
their appearance in Utah the latter part of February. In the Ken- 
newick territory only a few stragglers were observed after June 20 
and all of these apparently were young. In central Utah, however, 
a few were seen as late as September 12 (1932). 

The young are born early in March, the litters numbering usually 
7 to 10. Jewett (1923, p. 191) records taking a female carrying 13 
embryos. 

Although mainly terrestrial, these little squirrels occasionally 
climb to the tops of bushes, where they keep a sharp lookout for ene- 
mies. Their voice is described by Vernon Bailey as "a fine, pro- 
longed, chippering whistle." Scheffer (in ms.) describes it as 
follows : 

The notes or calls of this ground squirrel are very high pitched and com- 
paratively faint, not nearly so sharp and clear as the chirp of a chipmunk of 
even smaller size. The more prolonged or sustained of the two common calls 
might readily be mistaken for the faint trill of an insect, while the clearer, 
chirping sound can scarcely be distinguished from certain notes of the horned 
lark. As the little animal enters its burrow on the nearer approach of sus- 
pected danger, it voices its final protest in chattering tones, faint but not 
uncertain. 

Food habits. — ^Like most of the ground squirrels, this species feeds 
mainly on green vegetation in the early part of the season and later 
upon the seeds and stems of grasses and other plants. Scheffer, at 
Kennewick, Wash., observed them feeding' on globemallow {Sphae- 
ralcea inunroana) ^ silver Indianwheat (Plantago purshii), downy, 
chess (Bromus tectoi'um), slender wheatgrass {Agropyron pauci- 
■flomm), Indian ricegrass {Oryzopsis hymenoides) .^ and tumblemus- 
tard {Norta altissima), these being the same plants fed upon by 
Gitellus washingtoni at Wallula, on the opposite side of the Columbia 
River. The squirrels have been reported to feed also on the leaves 
and seeds of sunflowers and the flowers of the bud sagebrush {Arte- 
misia spinescens) . They consume also grasshoppers, cicadas, and 
many other insects. When in contact with agricultural crops they be- 
come a serious pest, destroying alfalfa, wheat, barley, potatoes, beets, 
carrots, lettuce, and other garden vegetables. They were reported in 
1917 to have practically destroyed a 10-acre field of beets at White 
Swan, Wash. 

EconomiG status. — This species was found by Francis (1922, p. 8) 
to harbor the infection of tularemia. 

SNAKE VALLEY GROUND SQUIRREL 

The Snake Valley ground squirrel {Citellus idahoetisis) has about 
the same habits as its near relative G. townsendii mollis. The squir- 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



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1938] REVISION OF THE GROUND SQUIRRELS 7 

rels inhabit the dry sagebrush plains and overflow into cultivated 
lands, where they prove destructive to crops of grain, alfalfa, and 
vegetables. They are reported to emerge from their hibernating dens 
in March, and by the middle of July they begin their period of estiva- 
tion. Each of four females taken at Nampa, Idaho, March 12, con- 
tained small embryos, numbering 8, 8, 9, and 10. 

WASHINGTON GROUND SQUIRRELS^" 

General habits. — ^AVashington ground squirrels {Citellus washing- 
toni subspp.) (pi. 1) occupy the dry prairies of the Columbia Basin, 
east of the Colmnbia Eiver. Vernon Bailey (in field notes) has 
described their habitat as follows : 

The country which they inhahit is open and either dry and sandy, grassy, 
or sagebrush covered. They are most numerous along steep hillsides, in 
gulches, and in sagebrush along river bottoms. On the smooth, grassy prairie 
they are common and more evenly distributed. They collect where some pro- 
tection is afforded by scattered bunches of sagebrush or Chriisotharnnus, but 
avoid any dense cover from which they cannot look out on all sides. 

Bailey estimated that in the section around Pendleton, Oreg., in 
1896 these squirrels averaged 50 to 100 per acre in the colonies exam- 
ined. On a measured acre on the prairie adjacent to a wheatfield he 
counted 620 burrows in addition to 62 larger holes dug by badgers in 
their search for the ground squirrels. The distribution of the squir- 
rels, however, is not continuous, and over most of their range they 
are less abundant than this estimate would indicate. 

A burrow of tliis species at Attalia, Wash., after having been 
fumigated with carbon bisulphide, was partly excavated by Scheifer, 
who states: 

At a depth of 4:^-2 feet and a distance of 11 feet down slope from the entrance, 
two half-grown squirrels were found suffocated. At 17 feet down slope from 
the entrance the burrow had reached a depth of hVi feet, which level it fol- 
lowed 7 feet farther— 24 feet in all. No branch burrow or nest had been found. 

Scheffer found the Washington squirrels out of their burrows at 
Wallula, Wash., on January 25 (1926). They were oiit in numbers 
at Almota, Wash., on February 23. In mild seasons, single individ- 
uals often emerge from hibernation as early as January 9. The ma- 
jority are reported to enter estivation during July, but Scheffer 
found that all had disappeared from their known haunts at Wallula 
and Attalia by June 16 (1925), when the weather was dry and hot. 
A few were seen at Coulee City as late as July 31, and one at Water- 
ville. Wash., on August 4. The young are brought forth in February 
or early in March, and by the last of March they are able to run 
about and feed on ^reen food. 

The voice of the Washington squirrels is said to be very much like 
that of Citellus townserulii mollis — a soft, lisping whistle. When 
their suspicions are aroused, the squirrels stand up at full length on 
their hind feet and give their alarm note as they watch keenly for the 
appearance of an enemy. The alarm is then repeated on all sides 
by other members of the colony. 

Food hahits. — Bailey examined about 30 stomachs of this species 
at Pendleton, Oreg., and found the contents to be almost exclusively 

2i> Formerly known as Townsend's ground squirrel (Citellus townsendii). For oxpla- 
nation of change of name see p. 70. 



8 NORTH AMERICAN FAUNA [No. 56 

of vegetable origin — green leaves, plant stems, wild flowers, bulbs, 
and seeds. Seeds of alfileria constituted over half of the food and 
were found in almost every stomach. Insects, consisting of a large 
caterpillar, a few small beetles, and several cicadas, were found in 
four stomachs. 

At Wallula, May 22 to 30, 1925, Scheffer studied the food habits 
of the Washington squirrels in detail, and made the following field 
notes : 

Examinations of the stomachs showed that they were not gorged to re- 
pletion with green stuff as they had been earlier in the season, but were filled 
to a more moderate degree with bits of succulent stems, buds, seed pods, and 
seeds. Plants on which they were observed to be feeding were globemallow 
(Sphaeralcea nmnroana), silver Indianwheat (Plantago purshU), downy chess 
{Bromus tectorum), slender wheatgrass (Agropyron pauciflorum) , Indian rice- 
grass (Orysopsis hymenoides), tumblemustard {Norta altissima), and to a 
limited extent, alfalfa, oats, and wheat. In every case the direct observations 
were supplemented by examination of the plants on the feeding grounds. In 
the case of the grasses both heads and stems were being used for food ; the 
favored part of the mallow seemed to be the small circular seed vessels, while 
only leaf tissue of the mustard appeared to be eaten. 

Economie status. — ^By reason of their great abundance and their 
fondness for grain, these ground squirrels rank as one of the most 
serious of agricultural pests. They extend their depredations well 
into the fields of growing grain, cutting down the stalks and eating 
only the tenderest portions, or at a later stage selecting only the 
fruiting heads. In some fields, in a strip around the edge two rods 
or more in width they destroy more than half the grain. They also 
invade gardens and feed on young cabbage plants, green peas, and 
young corn. 

RICHARDSON'S GROUND SQUIRREL 

General habits. — Richardson's ground squirrel {Citellus richard- 
sonii richardsonii) (pi. 2) lives on open prairies and on flats along 
the shores of lakes and rivers, seeming to prefer the sandy or gravelly 
ridges. In farming regions, the animals move into grainfields and 
pastures, and in some localities they occur in great abundance. 
Seton (1928,_p. 261) describes a colony at Whitewater, Manitoba, 
which he estimated to number 10 squirrels to the acre. He states, 
also, that at Carberry, Manitoba, in the early eighties, he often noted 
as many as 50 on a single acre, and captured 20 within an hour in 
two traps. At the approach of an intruder, they stand flat on the 
hind feet, the body erect entirely off the ground and the front feet 
hanging down on the chest. This habit has given the species the 
common name of "picket pin." When alarmed they whistle vigor- 
ously and when chasing one another they squeal loudly. In enter- 
ing their burrows, after halting at the entrance and lifting the head 
to watch the enemy, they go in head first usually switching the tail 
spasmodically. They quickly disappear with a final flirt of the tail, 
if danger still threatens. 

James Silver excavated and measured nine burrows of this species 
in North Dakota and found that the tunnels varied in length from 
about 12 to 49 feet and in depth below the surface from 3 feet 10 
inches to 5 feet 8 inches. Most of these burrows contained a cavity 
6 to 9 inches in diameter in which was a nest made of dry or green 
grass, straw, and oat hulls. 



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1938] REVISION OF THE GROUND SQUIRRELS 9 

Apparently the dates of entering and leaving the hibernation dens 
vary considerably with local conditions. Ranchers in central Mon- 
tana reported the squirrels as appearing in February, and Seton 
(1928, p. 264) quotes A. S. Barton in the statement that these squir- 
rels came out during February (1905) in the country around Boisse- 
vain, Manitoba. At Cando, N. Dak., they were first observed in 
1915 on March 10. In Alberta, on April 6, 1920, Francis Harper 
noted them in numbers at many points along a railroad between 
Calgary and Wetaskiwin. 

In North Dakota, practically all the adults go into estivation in 
July, while the young remain above ground until September or later. 
At Waterton Lake, Mont., August 14, 1917, Vernon Bailey noted 
many burrows of this species but only a single animal, and thought 
that most of them had estivated on account of the drying up of the 
vegetation. At St. Mary Lakes, Mont., they were numerous and ac- 
tive on August 24. At Bismarck, N. Dak., most of the squirrels had 
denned up by September 1, but at Blackfoot, Mont., they were still 
numerous above ground on September 12, and at Van Hook, N. Dak., 
on October 16, one was seen out after a very cold night. 

K. F. Ebner, of Cando, N. Dak., made notes on the disappearance 
of these squirrels in the fall of 1914; he stated that during the sec- 
ond week in September they appeared only on pleasant forenoons, 
and if disturbed would go into holes and remain the rest of the day ; 
that after about October 1, they would remain in their burrows for 
2, 3, and sometimes 4 days in succession, even in pleasant weather; 
and that none were seen from October 15 to November 2, but on the 
latter date they were unusually lively in the pasture. 

Richardson's squirrels produce but one litter a year, numbering 
from 6 to 11, with an average of 7.5. The period of gestation, as 
determined by U. S. Ebner, from specimens kept in captivity, is 
about 28 to 32 days. The young squirrels appear above ground at 
various times from April 20 to June 1. Ebner dug out a number of 
burrows in fall, without finding any store of food. 

The voice of this species is described as a short, shrill, whistling 
note. The animals are ordinarily not suspicious, and when taken 
young some make gentle and attractive pets, while others remain 
wild and vicious. 

Food hahits. — On the prairies, these squirrels subsist on the native 
grasses and flowering plants. They consume also seeds of various 
plants, including bindweed and sagebrush, and capture many grass- 
hoppers and caterpillars. Grainfields attract them and there they 
destroy quantities of grain, both in narrow strips along the edges 
and also around their burrows in the middle of the field. Follow- 
ing planting they dig up and eat the seed grain. Early in the sea- 
son they cut off and eat the succulent stems, and when the grain is 
ripening they pull down the stalks and cut off the heads. 

Seton (1928, p. 270) tells of finding in the pouches of one of these 
ground squirrels 240 grains of wheat and nearly 1,000 grains of 
wild buckwheat. He records also finding about 2 quarts of sprouted 
wheat in a squirrel's den that had been raided by a badger in fall. 



II Q NORTH AMERICAN FAUNA [No. 56 

WYOMING GROUND SQUIRREL 

General habits.— The Wyoming ground squirrel {Gitellus richard- 
sonii elegans) inhabits the sage and greasewood plains, chiefly in 
the Transition Zone and partly in the Upper Sonoran. The annuals 
reach comparatively high elevations in sections where grass-covered 
flats occur on a gravelly soil, but in general they avoid wooded or 
brush-covered areas. In many localities their burrows cover the 
ground more thickly than prairie dog mounds, and the population 
has been estimated to average at least 20 squirrels to the acre. The 
burrows are usually more numerous bordering cultivated fields, or 
in grassy patches in the semidesert regions. In irrigated districts, 
these squirrels concentrate in large numbers along roadways, railway 
embankments, and irrigation ditch banks, where the burrows are 
safe from the irrigation waters. 

In the Green River Basin, Wyo., the first of these squirrels to 
emerge from hibernation were reported on April 2, and by April 12 
they were out in great numbers. A female taken at Opal, Wyo., 
April 21, contained 5 small embryos. Burnett (1920, p. 8) records 
that 14 females examined in 1916 had an average of 8.2 young, and 
19 examined in 1920 an average of 4,6. He states that the young 
are born about the middle of May. By the middle of August the 
squirrels are fat and ready to begin their long sleep underground. 
Bailey reports that at Meeker, Colo., most of the ammals had gone 
into winter quarters by August 10, though several were seen on 
August 12. At Lay, Colo., A. G. Wallihan reports that they retire 
about the middle of July. 

Food habits. — Stomachs of 5 adults examined at Elk Creek, Idaho, 
were largely filled with ripe fruit of Amelanchier alnifoUa, together 
with green foliage, flowers of a composite, seeds of grasses, and a 
few remains of grasshoppers. Two individuals taken in the Laramie 
Mountains, Wyo., had their stomachs filled with the blossoms of 
rabbitbrush (Ohrysothamnus) , and one taken at Cheyenne had its 
pouches full of the heads of grama grass. A specimen of C. r. neva- 
densis taken in Malheur County, Oreg., had its pouches filled with 
1,160 fruiting capsules with seeds of Collomia. 

Economic status. — ^Wherever these ground squirrels come in con- 
tact with agricultural operations they become a serious pest. They 
consume large quantities of range grasses and in grainfields pull 
down the stalks and consume the heads of grain. They are especially 
destructive to growing barley and oats. Ranchmen in Moffatt 
County, Colo., claimed that in 1906 this species destroyed fully a 
third of the local rye crop and that they ruined a 5-acre field of 
oats in the same county. Carrots, radishes, lettuce, and other garden 
crops are sometimes damaged by these squirrels. Near Laramie, 
Wyo., a promising head-lettuce industry was threatened when the 
squirrels nibbled into the growing heads and so deformed them that 
an imperfect product resulted. Plague infection was demonstrated 
in a specimen of this squirrel taken in 1935 near Dillon, Mont. 
(Meyer, 1936, p. 964). 

UINTA GROUND SQUIRREL 

General habits. — ^The Uinta ground squirrel {Gitellus armatus) 
occupies dry meadows, pasture lands, and cultivated fields in high 



i 



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1938] REVISION OF THE GROUND SQUIRRELS H 

valleys, and ranges in the mountain meadows nearly to timber line 
(Wind River Mountains, Wyo., 10,500 feet). The animals seem to 
prefer moist locations near water, especially where the vegetation 
is rank. They live in large colonies in burrows dug in soft soil in 
the meadows or along irrigation ditches. Occasionally they climb 
into bushes. Their voice is said to be louder than that of C. elegans; 
their call is described by Merritt Gary as "a sharp, vibrant, bird-like 
Avhistle, often terminating in a trill." According to O. E. Stephl, 
they have another call, consisting of three distinct notes, repeated 
rather slowly. Like some others of their tribe, they spend only 
about 5 months of the year above ground, the remaining period 
being spent in estivation and hibernation. In Yellowstone Park, 
nearly all the adults disappear by the middle of August and by the 
end of that month only an occasional immature individual is seen 
above ground. A very late record is that of a specimen collected 
at Mammoth Hot Springs, Yellowstone Park, October 4 (1902). 
The first to come out in spring appear usually from about April 5 
to 11, though occasionally one may be seen as early as March 17. 

Food habits. — Little of a definite nature is on record concerning 
the food habits of this species, but reports of field collectors show 
that, like other related species, these ground squirrels feed on green 
vegetation and dry seeds. Stomachs of 10 specimens examined by 
A^ernon Bailey in Star Valley, Wyo., were full of green herbage, 
flowers of rabbitbrush {Chrysothamnus) , and seeds of grasses and 
other plants. Two contained some golden currants (Rlbcs aureum) . 
That these squirrels relish meat is evidenced by Bailey's statement 
that they ate two pocket gophers caught in his traps. 

Living chiefly in mountainous country, the Uinta ground squirrels 
come in conflict with agricultural interests less frequently than do 
many of the other species, but wherever their range extends into 
cultivated valleys, they damage crops to some extent. Plague has 
been demonstrated in specimens of this squirrel taken in Bonneville 
County, Idaho, in 1936 (Meyer, 1936, p. 965). 

BELDING'S GROUND SQUIRREL 

General habits. — Belding's ground squirrel {Citellus beldingi 
beldingi) (pi. 3) inhabits mountain meadows near timber line in the 
Sierra Nevada and is only rarely found in open timber or brush lands. 
Their burrows are dug beneath stumps, logs, or rocks, or sometimes 
out in an open meadow, and frequently they appropriate the tunnels 
of pocket gophers {Thomomys) for their own use. The period of 
hibernation in this species is not definitely known but evidently in 
the high mountain meadows these squirrels are able to obtain an 
abundance of green food all summer and consequently they remain 
active considerably longer than do other species living in the dry 
valleys at lower altitudes. Grinnell and Dixon (1918, p. 6G4) report 
these squirrels numerous in Tioga Pass, Calif., on September 28 and 
some out as late as October 7 near Ten Lakes, Yosemite Park. At 
Lake Tahoe, J. A. Loring found them out in numbers on May 18. 
Grinnell and Storer (1924, p. 173) mention a specimen obtained at 
the Farrington ranch, near Williams Butte, on April 29, 1916. The 
young are born about the first of July. 



12 NORTH AMERICAN FAUNA [No. 56 

The voice of this species is said to resemble that of the Oregon 
ground squirrel, according to Grinnell and Dixon (1918, p. 662) — 

The usual call of warning consists of a series of from five to eight short 
shrill whistles uttered in quick succession and weakening toward the last. 
F'emales warn their young when foraging abroad with -a lower-pitched, double 
note, or bark, e-chert. A single note, sirt, is also frequently heard. 

Food hahits. — Belding's ground squirrel feeds largely on the stems 
and seeds of wild grasses. C. Hart Merriam reports the species 
eating the flowers of beardtongue {Pentstemon confertus). Edmund 
C. Jaeger (1929, p. 91), writing of these squirrels as observed in 
July near Bishop Pass, Calif., says : 

Their principal food at this time was the half-ripe seeds of a phacelia, the 
fruit of which was borne on stout stems about seven inches from the ground. 

In Long Valley, Mono County, A. Brazier Howell (1924, p. 33) 
found them feeding extensively on a species of cicada {Okanagana 
magnifica) . C. Sharsmith (1936, p. 12) records instances where these 
squirrels had killed a junco, an Audubon warbler, and a chipmunk. 
Since the range of Belding's squirrel lies above the zone of agricul- 
ture, the animal is of no special economic importance. 

OREGON GROUND SQUIRREL 

General habits. — ^The Oregon ground squirrel {Citellus heldingi 
oregonus) lives chiefly in mountain meadows but also in pastures, 
meadows, and grainfields in the valleys, and to a less extent in open 
pine forests. It avoids marshy ground as well as rocky or brushy 
slopes. It lives in large colonies, especially on ranches where food is 
abundant. Ira N. Gabrielson reports a count of 466 on a 2-acre 
tract in Klamath County, Oreg. On a ranch in Butte Valley, Calif., 
Grinnell and Dixon (1918, p, 654) estimated 560 burrows on 1 acre. 
One burrow they excavated was 66 feet long, including the various 
windings and its branches ; its greatest depth below the surface was 
45 inches. 

These squirrels are almost exclusively ground dwellers ; very rarely 
have they been observed to climb into bushes to obtain seeds. Their 
voice is described by Bailey as "a rattling chipper., or series of sharp 
chips so rapidly uttered that they almost blend into a prolonged 
trill." 

Hihernation. — The Oregon ground squirrel spends more than half 
the year in a dormant condition. The date of entering hibernating 
quarters varies with the dryness of the summer and the supply of 
green vegetation. During some seasons, in the valleys, most of the 
squirrels disappear by July 10, but in seasons of greater rainfall they 
remain out several weeks longer; in the mountains, small numbers 
may be seen above ground as late as the first of September. In 
spring they begin to appear about the middle of February and by 
the first week in March are usually out in force, even if obliged to 
burrow through a foot or more of snow to reach the surface. At 
low altitudes in Umatilla County, Oreg., some have been reported 
out as early as January 22. 

Breeding. — This species produces one litter of young a year, vary- 
ing in number from 4 to 12, with an average of about 8. The young, 
born about April 10 to 20, appear above ground about May 10. In 
Butte Valley, Calif., on May 16, Grinnell and Dixon (1918, p. 658) 
report young out of the burrows in numbers, all about one-fourth to 
one-third grown. 



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1938] REVISION OF THE GROUND SQUIRRELS 13 

Food hahits. — The food of the Oregon ground squirrel consists 
mainly of green vegetation. In addition to grasses and cultivated 
grain, the following plants have been identified in the stomachs or 
cheek pouches : Flowers, stems, and leaves of camas ( Quamasia qua^ 
mash)^ buttercup {Ranunculus)^ springbeauty {Claytonia), shoot- 
ingstar {Dodecatheon) ^ mule-ears (Wyethia atnpIexicauJis) , sage- 
brush, and alfileria. Grasshoppers, crickets, and other insects are 
eaten by the squirrels, and 18 caterpillars from one stomach were 
recorded by Bailey. The squirrels have been reported to catch and 
kill young chickens and to devour their own kind found caught in 
traps. 

Economic status. — Grinnell and Dixon consider this species second 
in economic importance in California to the California ground squir- 
rel; they point out that these squirrels occur in great abundance in 
the grasslands and do serious damage to range grasses. Also, in 
some sections, they inhabit fields of alfalfa and grain — wheat, oats, 
and r3'e — and destroy a large proportion of the crops. 

This species has in recent years been found to carry bubonic plague. 
Surveys made during the summer of 1934 in Modoc County, Calif., 
resulted in finding the disease in 5 percent of the squirrels shot or 
found dead in an area of 65,000 acres. In April 1935, plague was 
proved in 107 Oregon ground squirrels (7 percent of 1,492 squirrels 
shot) in Modoc County. A fatal case of human plague occurred at 
Lakeview, Oreg., in May 1934, probably contracted from a ground 
squirrel of this species (Meyer, 1936, p. 964) . 

COLUMBIAN GROUND SQUIRREL AND RELATED RACES 

General hahits. — The Columbian ground squirrel and related races 
{Gitellus columhianus subspp.) (pi. 4) live in a wide variety of 
habitats, from the open prairies of eastern Washington to the moun- 
tain parks at an altitude of 7,000 or 8,000 feet. Apparently the 
animals prefer rough, rocky, half-forested hillsides, but in many 
places they are numerous in hay meadows, grainfields, stony pastures, 
and open pine flats. They live in colonies but are somewhat less 
gregarious than prairie dogs. They spend the greater part of the 
daylight hours gathering and consuming food from an area rather 
close about their burrows, seeking safety in their dens when danger 
appears, but if the food supply is limited near their dens, they often 
make somewhat extended trips in search of some favorite item. 

These squirrels are rather noisy, and in a colony their alarm note — 
a clear, sharp chirp., repeated a number of times — is almost con- 
stantly heard from sunrise to sunset. In places where they are per- 
secuted by man and also in wilderness areas remote from civilization 
they are usually shy and are difficult to approach closely. When 
given protection, however, as in some of the national parks, they 
become so tame that they will take food from the hand. 

Burrows and nests. — The burrows of these squirrels are dug be- 
neath logs, stumps, or boulders and descend at an angle of about 45°. 
Vernon Bailey (1918, p. 47) describes a summer den that he ex- 
cavated near Piegan Pass, at 7,000 feet altitude in Glacier National 
Park, Mont., as follows : 

The mound at the entrance of the burrow contained about 4 bushels of earth 
and stones brought from the burrow, and the lower part was packed and hard as 
though an accumulation of several years. Tliere were two other openings 



14 



NORTH AMERICAN FAUNA [No. 56 



farther back from which no earth had been thrown and evidently they had been 
tunneled to the surface from below. The main shaft of the burrow was usually 
3 or 4 inches in diameter, and back a couple of feet from the entrance, just 
before the burrow forked into two main shafts, was a roomy chamber where 
the squirrels could turn around and sit up comfortably, a sort of reception 
room. Near secondary forks were also two other chambers which may have 
served several purposes, such as convenience in storing earth brought out of 
the tunnels, or places of retreat from which to watch for enemies that might 
enter the burrow from either direction. Well back about 8 feet from the 
entrance and a foot below the surface of the ground was a large nest chamber 
about a foot in diameter nearly filled with old soft nest material. The nest 
was composed almost entirely of the soft flat leaves of the brown "glacier 
grass" (Juncoidcs parviflorum) which abundantly covers the mountain slopes. 
At the bottom it was damp and moldy, but from the bed in the center to the 
top it was dry and clean, and a few fresh, green blades had been brought in 
for food or nest material. It had evidently served as winter quarters for the 
old squirrel and as a nest for her young and was being prepared for the coming 
winter. From one side of the nest chamber the burrow led down to an older 
and deeper chamber of some previous year, containing at the bottom an old 
rotten nest half full of excrement. A tunnel ran from it back toward the main 
entrance and into the main tunnel near the middle, making an easy way of 
escape if an enemy should dig to the first nest. Back of the nest a small shaft 
led to the surface of the ground and another opened out at the end of the first 
main fork of the tunnel. These rear openings were half concealed in the grass 
and evidently were for use as avenues of escape in case the burrow should be 
entered by a weasel or dug out by bear or badger. 

Estivation and hibernation. — This species spends from Y to 8 
months annually in a dormant condition. Those individuals living 
in the valleys and on the prairies become very fat by midsummer, 
and from July 15 to 30 a noticeable decrease in their numbers is ob- 
served as some of them enter estivation. In eastern "Washington, in 
dry seasons by July 29 and in wet seasons by August 11, all have 
entered their dens for the long sleep (Shaw, 1925a, p. 75). These 
squirrels do not as a rule drink water, but depend upon succulent 
vegetation to supply needed moisture. Apparently the date of be- 
ginning estivation is determined chiefly by the ripening of the vege- 
tation and consequent reduction of the moisture content in their food, 
and in part also by the accumulation of fat in the body. 

At Osborn, Idaho, the last of the ground squirrels disappeared 
following a first frost on August 8 (1895) . In the Bitterroot Valley, 
Mont., all had begun estivation by August 25 (1909). In the moun- 
tains, at higher altitudes, some of the animals remain out until the 
first week in October (Woodman Creek, west of Lo Lo, Oct. 7) . A 
single individual was taken near Kalispell, Mont., on October 1 
(1932). 

At Pullman, Wash., the first squirrels came out of their hiberna- 
tion dens on February 21 (1913), March 1 (1912), and March 8 (1911 
and 1917). At Endicott and St. Johns, Wash., they first appeared 
from February 2 to 9 (1909). In the Bitterroot Valley, Mont., the 
first were seen on March 6 (1910), and March 25 (1912), and by 
March 31 they were out in full numbers. 

The hibernation dens have been studied and described by W. T. 
Shaw (1925b, fig. 2, opp. p. 58), who states: 

A hibernation den is frequently a part of an ordinary den shut or sealed off 
from the main den by having all connecting burrows very effectiially plugged. 
It may, however, be quite remotely hidden away from the large summer den. 

Of 50 hibernation cells measured, the average depth below the 
surface was found to be 2 feet 6 inches; the shallowest cell was 6 



1938] REVISION OF THE GROUND SQUIRRELS 15 

inclies below the surface, the deepest 4 feet 11 inches. Occupied 
dens are sealed by the squirrels with a plug of earth 2 feet or more 
in length, tamped in. For most of the hibernation dens (except 
those on a side hill) drainage is provided to carry water away. 
In some cases an exit shaft leading toward the surface is provided. 
When ready to come out in the spring the animal digs its way to the 
surface, placing the soil removed in the bottom of the burrow, thus 
leaving no loose dirt at the entrance. 

Storage of food. — Food supplies are stored in the hibernation dens 
to a limited extent. Regarding this habit, Shaw (1925b, fig. 11, opp. 
p. 79) writes as follows: 

Very unexpected iufonnatiou has been found in connection with the matter 
of the food supply being stored for the winter. The nests of female and imma- 
ture squirrels are almost without exception lacking in a store of food. The 
uests of the old males, on the other hand, very frequently, though not always, 
have a cache of some kind of food. Strange to say, in this stored supply 
they seem to prefer some wild seed or bulb to grain, and nests found in wheat 
fields are frequently stored with some wild seed. Furthermore, they usually 
use but the one kind of seed, or bulb, in a nest at a time, though several kinds 
of seeds and bulbs have been found in the various uests discovered. In this 
connection it is interesting to note that the old male squirrels appear a week 
to 10 days before the females and immature, often when the weather is bad 
and food scarce, hence the need of food. It is also of interest to note that the 
store, which is found in the mulch or bottom of the nest, seems not to be 
touched during the winter, as several interesting observations tend to show, 
but is reserved until the time of awakening in the spring. 

Breeding. — The number of young in a litter varies from 2 to 5, 
rarely 7, averaging about 3.5. The gestation period, as determined 
by Shaw (1925d, p. 108) from animals kept in captivity under semi- 
natural conditions, is 24 days. The rutting season begins about 
March 15 to 20, and Shaw records capture of a wild adult at Pullman, 
Wasli., on April 6, carrying G fully formed embryos. At Ford, 
Idalio, James Silver examined 25 females on April 10 that were 
carrying large embryos ; on April IG, 13 females showed evidence of 
having recently borne young. Probably in the mountains most 
young are born early in May; at Nyack, Mont., however, a female 
was captured on June 24, 1895, carrying 3 embryos. The young are 
able to leave the nest in about 4 weeks after birth. At Pullman, 
young were first observed out of their dens between May 4 and 10. 

Food habits. — The food of the Columbian ground squirrel com- 
prises a great variety of vegetable substances and a small proportion 
of animal matter. A large part of the vegetable food consists of wild 
and cultivated grasses, herbs, and fruits, including the bulbs of 
camas, wild onion, and glacierlily {Erythronium grandifiorum) ; 
stems, leaves, and flowers of false-hellebore (Veratrum), buttercups, 
roses, dandelions, mule-ears (Wyethia) , balsamroot (Balsamorhisa) , 
camas {Quamasia quamash).^ lupine, and wild lettuce; currants, 
gooseberries, strawberries, and serviceberries (Amelanchier) . 

On cultivated lands the squirrels consume the stems and heads of 
clover, alfalfa, bluegrass, oats, rye, wheat, and barley ; vines of pota- 
toes, beans, and peas ; lettuce, carrots, and probably other vegetables. 

Grasshoppers, cicadas, and caterpillars are frequently eaten, and 
sometimes fish, if the habitat borders a lake. 

Economic status. — Wherever it comes in contact with agriculture 
the large Columbian ground squirrel is destructive, particularly to 



-j^g NORTH AMERICAN FAUNA [No. 56 

grain, clover, and pasture. When uncontrolled, the animals become 
numerous and may destroy practically entire crops in the area where 
they are living. Shaw (1925g, p. 264), writing of the section around 
Pullman, Wash., says: 

During 7 successive years, 7,000 squirrels were trapped on 416 acres of the 
college farm, or 2.4 squirrels per acre each year. A successful wheat raiser 
near Steptoe, V/ash., trapped 1,200 squirrels on 200 acres in 1 year, or 6 
squirrels per acre. 

Shaw's experiments showed that single animals kept in confine- 
ment under natural conditions in the course of a season destroyed, 
on an average, 50l^ pounds of winter wheat. 

This species has been shown to be in large part responsible for the 
dissemination of Rocky Mountain spotted fever, Birdseye (1912, p. 
10), reporting on his studies in the Bitterroot Valley, Mont., says 
that it is undoubtedly the most important host of the two younger 
stages of the fever tick, and is almost always infested with ticks 
Avhen occurring in suitable country. Plague infection was demon- 
strated in specimens of this species taken in Wallowa County, Oreg., 
in 1935 (Meyer, 1936, p. 964). 

PARRY'S GROUND SQUIRREL AND RELATED RACES 

General habits. — Richardson (1825, p. 319), writing of Parry's 
ground squirrel {Gitellus parryii 'paiTyii) as observed on the Arctic 
coast between the mouth of the Mackenzie and Bathurst Inlet, says : 

The gray Arctic marmot is common in stony barren tracks, but delights chiefly 
in sandy hillocks, amongst rocks, where it burrows, living in society. 

Anderson (in Stef ansson, 1913, p. 510) , writing also of the Arctic 
coast in the same region, says that these squirrels Avere found at 
many points along the coast in sandy clay hills and were particularly 
abundant in sandy alluvial river bottoms. Along the Mackenzie 
River, below Fort Good Hope, E. A. Preble found the animals liv- 
ing in burrows in the clay banks, well above high- water mark. On 
the Barren Grounds near Cape Eskimo, Hudson Bay, he found them 
occupying gravellj^ ridges, either old shore lines, or deposits left in 
the process of glaciation, and around Artillery, Clinton-Colden, and 
Aylmer Lakes, Seton and Preble (Seton, 1911, p. 342) found them 
frequenting similar situations. 

In McKinley Park, Alaska, O. J. Murie reported the subspecies 
G. 'p. plesius numerous in the valleys, on the slopes, and on the ridges. 
Some had dug their burrows among willows and in vegetation on the 
slopes, and others lived among rocks. A burrow dug out there was 
found to have two entrances and many ramifications; its greatest 
depth was 27 inches. In the Delta River region he found the squir- 
rels inhabiting the river bars and the flats among the dwarf birches 
and willows, as well as on the hills where cover was scarce. In 
northern British Columbia, Preble found them in broad nearly level 
valleys clothed with shrubby vegetation, or on the gentle lower slopes 
of mountains, and seldom or never above timber line. 

Richardson speaks of the alarm note of this species as "a kind of 
a whistle", and when the animal is in terror this note is said to re- 
semble the sound of a watchman's rattle. 

HibernaMon. — R. M. Anderson (in Stefansson, 1913, p. 510) states 
that on the Arctic coast, most of these squirrels go into hibernation 



19381 REVISION OF THE GROUND SQUIRRELS 17 

the latter part of September, though a few remain out until the 
middle of October ; and that they reappear in spring about the middle 
of April. At Collinson Point, however, on October 2, they were out 
in some numbers, and at Point Barrow individuals have been taken 
on October 15, November 10, and December 3. At Wiseman, on the 
south slope of the Endicott Range, two ground squirrels were seen 
by O. J. Murie on October 23 (1924). 

At Cold Bay, the Alaska Peninsula race {G. p. ablusus) was active 
in some numbers as late as October 18 (1902) (Osgood, 1904, p. 32), 
and at Togiak, Alaska, a specimen was collected on March 10 (1897). 
At Chignik, Alaska, during the mild winter of 1911-12, the squirrels 
were seen occasionally throughout the winter and a specimen was 
captured on February 13. The small mountain form {G. p. plesius) 
was observed at Teslin Lake, Yukon, on October 3 and specimens 
were taken in the Tanana Hills, Alaska, on March 4. 

Breeding. — Richardson (1825, p. 318) records taking a female that 
contained seven embryos at Pomt Lake, Mackenzie, on June 13. 
Judging from the size of two young individuals taken at Old Fort 
Good Hope, Mackenzie, it seems probable they were born about the 
middle of May. Echnund Pleller recorded a female of G. p. plesius 
suckling young on June 10, and another carrying a single large 
embryo on June 11, at Telegraph Creek, British Columbia. 

Food habits. — Richardson (1825, p. 319) reported the food of 
Parry's ground squirrels to be entirely of vegetable origin. He says : 

In upwards of 50 individuals examined at various periods, no animal sub- 
stance was detected in the pouches or stomachs. At Point Lake in lat. 65°, 
their pouches were observed about the middle of June to be filled with the 
berries of the Arbutus alphia and Vaccinium vttis-idaea, which were just then 
laid bare by the melting of the snowy covering, under which they had Iain all 
winter. In the end of July, on the shores of the Arctic Sea, their pouches 
contained the seeds of a Polygonum, and in Five Hawser Bay in September, 
they were filled with the seeds of astragali. 

At Aylmer Lake, Seton (1911, p. 237) obtained a ground squirrel 
with its cheek pouches full of mushrooms. 

Anderson (in Stefansson, 1913, p. 510) states that along the Arctic 
coast, the squirrels fed mainly on the roots of various species of 
Polygonum. 

The stomach of a specimen of G. p. ablusus, taken on Unimak Island, 
Alaska, May 8, 1925, and examined in the Biological Survey, con- 
tained the following materials: 21 caterpillars and lepidopterous 
pupae, 60 percent; 1 tipulid larva and 5 Bibio larvae, 4 percent; 2 
beetles {Gryobius sp.) ; 1 ichneumonid and a spider, trace; 2 berries 
{Vaccinium sp.), 2 percent; a few leaves of Empetrum nigrum and 
other vegetable matter, 34 percent. 

YUKON VALLEY GROUND SQUIRREL 

General habits. — Osgood (1900, p. 31) describes the habits of the 
Yukon Valley ground squirrel {Gitellus osgoodi) as follows: 

From Fort Selkirk, near the limit of Spermophilus plesius in the interior, 
nearly to Circle, we saw no signs of ground squirrels of any kind. Just before 
reaching Circle, however, we began to see unmistakable signs of them and were 
soon attracted to a small colony by their clicking calls which reached our eai-s 
as we floated down in midstream. The call is executed in about the same time 
as that of 8. plesius, but its pitch is much lower and its effect on the ear is 
154970—38 2 



Ig NORTH AMERICAN FAUNA [No. 56 

utterly different. It suggests the click of castanets. On going ashore we found 
their burrows and connecting paths scattered over quite an area on the hillside. 
The colony occupied the open hillside and a few ledges of loose rock, and even 
extended down into a thicket of alder and willow at the foot of the hill. The 
animals were very shy and became much excited at our approach. Their 
long tails were very noticeable in marked contrast to the short ones of 8. 
vlesius, which we had been accustomed to seeing. 

Writing of his second trip down the Yukon, Osgood (1909, p. 22) 
writes of these ground squirrels as follows : 

Many of their burrows are made in the sandy banks of the river, often only 
3 or 4 feet above high-water mark, and usually open under the overhanging 
turfs of the bank or among the exposed roots of trees and shrubs. Higher up 
they are variously situated on the hillsides, where the little boreal sagebrush 
{Artemisia frigida) flourishes. As a rule, however, the hillside burrows are 
not in exposed places, but are more or less sheltered by small bushes near 
the edge of the timber. The animals were rather quiet and seldom gave their 
clicking cry except when alarmed. They fought viciously when being taken 
from traps, often lunging at vis with mouth open and claws spread. Several 
were seen at the water's edge, and tracks were abundant on the damp sand, 
but whether or not they drink there was not ascertained. Nearly all the 
females taken had the mammae distended with milk. Apparently most of the 
young were too small to leave the burrows. At one place 5 little squirrels all 
of a size and evidently from the same mother were caught in rapid succession. 
Of these, 4 were normal in color and the fifth was in the black phase. Among 
adults the black phase was found in about the same proportion. 

STRIPED GROUND SQUIRRELS 

General habits. — The striped ground squirrels {Gitellus tridecem- 
lineatus subspp.) dwell chiefly on dry grassy prairies and to a less 
extent in sandy river bottoms and the brushy borders of tmiber 
tracts. They are gregarious only to a slight extent, and not at all 
sociable, individuals usually living a more or less solitary life and 
often digging a number of burrows, some of which are shallow and 
are used for temporary shelter and others of more elaborate con- 
struction for more permanent use. These latter are ordinarily in 
the hard soil of upland pastures or meadows and are said always to 
have two entrances. They descend steeply for a short distance, 
then extend horizontally. They may be as much as 20 feet in length 
and from 4 to 46 inches in depth. Usually there is no earth piled 
around the entrance, the rim of the burrow being level with the 
surface and thus quite inconspicuous. Frequently the burrows are 
plugged with earth by the squirrels after entering, especially during 
hibernation. Sometimes abandoned burrows of other rodents are 
used, including those of prairie dogs, kangaroo rats, and pocket 
gophers. 

Nests of dry grass of a spherical shape are found usually in the 
longer permanent burrows, at depths varying from 3 to 29 inches 
(Johnson, G. E., 1917, p. 264). The nests are used in spring to house 
the young, in summer for storage of food supplies, and in winter 
for hibernating quarters. 

Breeding activities are at their height during April, and the 
young, numbering from 5 to 13 (commonly 6 to 10), are brought 
forth ordinarily in May or early in June. The gestation period is 
given by Wade (1927, p. 271) as between 27 and 28 days. 

The note of this species is described by Bailey as "a rapid bird- 
like trill or trembling whistle — a long drawn-out chur-r-r-r-r in a 
high key." 



1938] REVISION OF THE GROUND SQUIRRELS 19 

Hibernation. — The date of entering on the winter sleep varies with 
season and locality. At Lincoln, Nebr., Wade (1930, p. 169) re- 

gorted that in 1927 nearly all had disappeared by the first week of 
eptember, while in 1926 they remained out much later, small ninn- 
bers being seen until October 17, when the last one was noted. In 
Colorado, according to Burnett (1914, p. 6), the latest date recorded 
is November 9, and the earliest date in spring, March 23. Other 
late fall dates are: October 30 (Illinois), November 3 (Springer- 
ville, Ariz.), and November 23 (Oklahoma). 

Wade (1927, p. 270) states that in the vicinity of Lincoln, Nebr., 
these squirrels emerge from hibernation between the middle of 
March and the first of April; in 1926 the first were seen on March 
17. Near Minneapolis, Minn., they were reported to appear 1 year 
on March 17 and 2 years on April 5. In southern Manitoba, accord- 
ing to Seton, they may come out as early as March 27, or in back- 
ward seasons as late as April 20. Johnson (Johnson, Foster, and 
Coco, 1933, p. 266) states that in west-central Kansas the males 
appear in numbers above ground usually about the middle of March 
and the females about the last of March or first of April. 

Food habits. — The striped ground squirrels feed on a variety of 
wild plants and seeds, in addition to cultivated grains, and are 
especially fond of grasshoppers and other insects. Bailey (1893, p. 
39) has given an extended account of the food of this species, in 
which he shows that more than half the contents of 80 stomachs 
examined consisted of insects, including grasshoppers, crickets, 
caterpillars, beetles, ants, and insects' eggs. The A^egetable matter 
comprised oats, wheat, cactus fruit, nightshade berries, roots, herb- 
age, and seeds of goosefoot {Ghenopodium)., knotweed {Polygo- 
num)^ and sunflower {Helianthus). Eleven cheek pouches of this 
species examined contained only seeds, including wheat, oats, millet, 
deervetch {Lotus), and seeds of porcupine grass {Stipa spartea), 
sunflower, gromwell {Lithospermum) , bristlegrass {Setaria), Pani- 
cum, ragweed {Ambrosia), and black locust {Robinia). To the list 
may be added cotton, clover, and flax seed, wild beans, and seeds of 
dandelion, vetch, ricegrass (Oryzopsis), gum weed {Grindelia), and 
the buffalo-bur {Solarium rostratum). Morris M. Green (1925, p. 
176) records the capture of a striped ground squirrel that had its 
cheek pouches bulging with 196 large seed pods of the sleepy catchfly 
{Silene antirrhina). 

Much of the dry food gathered by these squirrels is stored in 
their burrows; concerning this habit, Kennicott (1857, p. 77) writes: 

Many of our farmers suppose that this animal feeds, in winter, upon stores 
of provisions laid up in its hole for that season; for, though it spends the 
winter in a state of profound torpor, it collects food in its hurrow. This is 
done in spring and summer, as well as in autumn. Considerable stores of 
grain, seeds, roots, &c., are found thus collected, in large sidechambers exca- 
vated for their reception in the burrow. Corn, wheat, and oats are stored 
up, when taken from the newly-planted fields in spring, with buckwheat and 
winter wheat later in the season, as well as heads of grain taken from the 
edges of the fields in harvest time. I have seen more than a quart of crab- 
apples taken from the burrow of one which had carried them several rods 
from a tree. George and Frank Kennicott inform me that they observed one, 
the burrow of which was near a lone burr-oak, on the prairie, to carry great 
quantities of acorns into his hole ; and another was killed by them, the cheek- 
pouches of which were crammed with the dry ovaries of a prairie plant, the 
seeds of which were exceedingl.v minute. From this, it would appear that the 



20 NORTH AMERICAN FAUNA [No. 56 

striped spermophile at all seasons carries portable articles of food to its bur- 
row to be eaten. He certainly takes no food from the time lie first becomes 
torpid, in autumn, until be again becomes active late in the following spring. 

Johnson records a burrow of this species in which the nest cavity 
was entirely filled with imshelled oat kernels, estimated to number 
about 23,000, and another burrow that contained- 2,000 or 3,000 wheat 
kernels. 

This species shows a rather decided taste for flesh food, and it has 
several times been reported to capture and kill mice (Bailey, V., 1893, 
p. 38), and small chickens (Bailey, B., 1923, p. 129; Green, 1925, p. 
175), and even to feed on the bodies of its own kind. 

Econotnic status. — The most serious charge against these ground 
squirrels is that they dig up and destroy newly planted corn. Wliere 
the squirrels are abundant, this habit may result in serious damage 
to a crop but ordinarily the depredations are confined to a few row,s 
on the edge of a field. Peas, beans, cucumbers, squashes, beets, straw- 
berries, and other garden crops are sometimes damaged, and fields 
of wheat or oats are occasionally drawn upon for supplies to be 
stored in the burrows. 

Against these destructive tendencies must be placed the evident 
fondness of the squirrels for grasshoppers, cutworms, webworms, and 
other injurious insects, the destruction of which undoubtedly exercises 
an important check on the ravages of the pests. Wherever the squir- 
rels occur on extensive grasslands they are distinctly beneficial, 

MEXICAN GROUND SQUIRRELS 

General ha'bits. — The Mexican ground squirrels {Citellus mexi- 
canus subspp.) inhabit sandy plains where there is a growth of cactus 
or mesquite, and both in Mexico and the United States they range 
out into cultivated fields of corn or other grain. Their burrows, 
usually situated at the base of mesquite or other bushes or on the edge 
of a bunch of cactus, descend nearly perpendicularly for a foot or 
more, then slope down at an angle still deeper. 

Apparently these squirrels do not hibernate, but they have the 
habit of plugging the entrance to their burrows after going in, and 
during cold weather they may remain under ground for considerable 
periods. Th&y are shy and usually silent, but Nelson states that they 
have a shrill, whistling note of alarm. 

Food ha'bits. — Bailey (1931, p. 115) reports this species feeding in 
about equal proportions on seeds and insects. Mesquite beans and 
seeds of Acacia are said to be favorite foods and doubtless many 
other seeds are eaten. At Langtry, Tex., Gaut found the squirrels 
feeding on the purple blossoms of a groundcherry {Physalis lobata) . 
They often range into cultivated fields and do considerable damage 
in spring by digging up corn, melons, beans, and sweetpotatoes, and 
later by eating ripening grain. 

SPOTTED GROUND SQUIRRELS 

General ha'bits. — The spotted ground squirrels {Citellus spilosoma 
subspp.) (pi. 5) seem to prefer dry, sandy soil for their habitation. 
They live in drifted sand along river flats, in grassy parks, in open 
pine forests, and to a less extent on rocky mesas. Their burrows 



North American Fauna No. 56. U. S. Dept. of Agriculture. Biological Survey 



PLATE 5 



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1938] REVISION OF THE GROUND SQUIRRELS 21 

are usually under a bush, in a weed patch, or under an overhanging 
rock. D. E. Lantz dug out a burrow at Hugo, Colo., that had three 
entrances and was about 12 feet in length, though nowhere more 
than 18 inches below the surface. It terminated in a small, rounded 
chamber in which was a slight nest of grass. In some localities the 
squirrels often appropriate the burrows of kangaroo rats or other 
rodents. Like most of the ground squirrels, they are strictly diurnal, 
but are rarely seen abroad during the heat of midday. They are 
shy and retiring and of gentle disposition, and when captured alive 
make attractive pets. Vernon Bailey describes their call note as 
"one long, bubbling, birdlike whistle." 

These little squirrels do not wander far from their burrows, and 
in running their movements somewhat resemble those of a lizard; 
the body is more or less flattened, the tail is held close to the ground, 
and the squirrel proceeds by short runs with frequent stops. 

Hibernation. — Hibernation in this species is apparently not com- 
plete, at least in the more southern parts of its range, but during 
severe winter weather the animals usually remain within their bur- 
rows. Specimens have been taken near Tucson, Ariz., from January 
27 on through February and March; at El Paso, Tex., February 9, 
20, and 21; in Lake Valley, N. Mex., November 13; at Deming, 
N. Mex., December 4 and 6; and at Chihuahua, Mexico, December 25. 

Food habits. — The food of these ground squirrels is largely green 
vegetation and seeds. The following items have been identified in 
their stomachs : Cactus pulp, mesquite beans, seeds of saltbush {Atri- 
plex)^ sandbur {Cenchrus)., sunflower, gourd, and iris; grasshoppers 
and beetles. Living mostly in uninhabited regions these squirrels 
are of little economic importance. They undoubtedly consume con- 
siderable grass and in cultivated areas are sometimes troublesome in 
digging up planted seeds, 

PEROTE GROUND SQUIRREL 

General habits. — Little is known of the habits of the Perote ground 
squirrel {Citellus jyerotensis) . Nelson reported that it lives in the 
plains, about the borders of wheatfields and cornfields. 

FRANKLIN'S GROUND SQUIRREL 

General habits. — Franklin's ground squirrel {Citellus frankUnii) 
(pi, 6) or the "gray gopher," as it is frequently called, inhabits 
prairies, bushy pastures, grainfields and hayfields, open groves of 
timber, and partly dry marshes, Kennicott (1857, p, 79), writing 
of its habits in Illinois, says : 

It is observed to inhabit the thickets of low bushes, and the edges of the 
timber, more than the other [C. tridecemlincahis], but does not occur in the 
woods. It is fond of digging long burrows in the banks of ditches, and several 
times I have seen it living in steep river banks, as well as under small wooden 
culverts in roads. It is not so shy as the striped spermophile, and takes up 
its residence quite near dwellings. 

Wood (1910, p. 528), writing from Illinois half a century later, 
says of these squirrels : 

At present a necessary condition for their habitation seems to be the presence 
of some shelter, such as may he furnished by tall grass, or a field of clover, 
alfalfa, or grain. Others have noticed that when the crop on such a field is cut 



22 NORTH AMERICAN FAUNA [No. 56 

the gophers leave, at least for a while, and my own observations coincide with 
theirs, though I have known the gophers to return to the same spot after the 
second crop of alfalfa had started. They avoid closely cropped pastures, 
well-kept cemeteries, lawns, and similar places where the striped gopher is 
especially abundant, yet ev^en in such localities I have found them congregated 
under a heap of compost. In fact such a shelter seems to have special attrac- 
tions for them, as noted by Bailey. ... 

The species is decidedly gregarious, nearly always being found in colonies. 
As their burrows each have several openings and these are conspicuously 
marked by the dirt thrown out, a colony becomes a great nuisance in a hay 
or grain field. The conspicuousness of these burrows and of the animals 
themselves has aroused the animosity of the farmers and hastened the de- 
struction of the gophers. 

Kennicott (1857, p. 80) describes their notes as "a remarkably 
clear whistle twitter, more musical than the voice of any other 
mammal I ever listened to, and as clear as that of a bird." 

HibemoMon. — Franklin's ground squirrel has been known to store 
up in September as much as half a peck of oats in a burrow under 
a shock. The animals, however, become excessively fat in fall and 
all retire to their burrows in October, where they remain in hiberna- 
tion imtil April. Bailey (1893, p. 52) gives dates of their appear- 
ance at Bathgate, N. Dak., as April 3 (1889) and April 21 (1890). 
Kennicott states that they have been found hibernating under piles 
of rails and in corn shocks, and in two instances in a hay stack. 
Eemington Kellogg states that he has found the animals torpid in 
a burrow about 3 feet underground. 

Breeding. — The young, 5 to 10 in a litter, are born in May or 
June; by the last of July, in North Dakota, they are out of their 
burrows foraging for food. Adults carrying embryos were taken at 
Elk River, Minn., on May 7, and at Carberry, Manitoba, on June 15. 

Food habits. — The vegetable food of this ground squirrel comprises 
about two-thirds of the total and includes clover, timothy, junegrass; 
leaves of plantain, mustard, and probably other wild plants ; wheat, 
oats, barley, newly planted corn* seeds of needlegrass (Stipa), cockle- 
burs, and basswood; strawberries and nightshade berries. Animal 
matter, found in 29 stomachs examined in the Biological Survey, 
consisted of beetles and their larvae, caterpillars, grasshoppers, 
crickets, ants, eggs of insects, and feathers of a small bird (Bailey, 
1893, p. 55). Individuals of this species have been known to kill 
and eat wild mice and a young rabbit, to rob a meadowlark's nest, 
to kill a wood pewee, to capture small chickens, and to eat hens 
eggs. 

Economic status. — ^In localities where these squirrels are abundant, 
they may do considerable damage to crops by digging up newly 
planted corn and in the fall by burrowing under corn shocks. They 
sometimes invade vegetable gardens and destroy peas and cabbage, 
and in grainfields they destroy considerable grain in the vicinity of 
their burrows. 

ROCK SQUIRRELS 

General habits. — The several races of the rock squirrels {Citellus 
variegatus subspp.) (pis. 7 and 8) have habits similar to other ground 
squirrels; all show such a decided preference for inhabiting rocky 
canyons and rocky mountain sides that their name "rock squirrel" 
seems quite appropriate. In central Mexico, the typical race {G. v. 
variegatus) is reported by Nelson and Goldman to live on rocky hill- 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 6 




1938] REVISION OF THE GROUND SQUIRRELS 23 

sides, along stone walls or irrigation ditches, and in cactus or mescal 
hedges, often ranging out into cultivated fields. Their burrows are 
dug usually under a large boulder or sometimes in thickets. Al- 
though typical ground squirrels, they climb trees readily in search 
of food, and occasionally make their homes in hollow trees as high as 
15 or 20 feet from the ground (Bailey, 1905, p. 85). They often 
climb to the tops of juniper trees to gather the berries, and into 
mesquite trees to eat the green buds or the beans. 

The rock squirrels are knov/n to store food extensively for use in 
winter, and it seems probable that over the greater part of their 
range they remain more or less active throughout the year. Wliether 
they ever actually hibernate is not known. During the colder parts 
of the year they are seen out of their dens only on mild, sunny days. 
Their food supplies, consisting chiefly of acorns, walnuts, and the 
seeds of peaches, plums, and apricots, are stored in earth burrows, 
in cavities in cliffs or under boulders, and in hollow trees. 

The voice of the rock squirrel is described as "a loud, shrill 
whistle — a single note repeated at irregular intervals" (V. Bailey, 
ms.). 

Food habits. — The food of the rock squirrels comprises a long list 
of vegetable materials and includes also grasshoppers, crickets, cater- 
pillars, and other insects. Nuts, including acorns, walnuts {JuglaTis 
rupestris), and pine nuts {Pinus edulis) probably furnish a large 
part of the yearly food. Other seeds that have been found in the 
cheek pouches or stomachs of these squirrels are tliose of mesquite, 
cactus, saltbush {Atriplex), wild gourd, wild cherries, muskmelon, 
watermelon, fragrant sumac {Rhus aromatica)^ Nevada jointfir 
(Ephedra nevadensis),servicebevry {Amelanchier) , spurge (Euphor- 
bia), and marbleseed (Onosmodium oceidentale) , and berries of the 
wax currant (Ribes cereum). The rock squirrels are reported to 
feed on wild figs, cactus fruit, blossoms of the mescalbean (Sophora 
secundifora) , and the flowers and tender tips of the agave, 

A specimen of Say's rock squirrel (O. v. grammuims) taken in New 
Mexico had its pouches stuffed with the berries of the cherrystone 
juniper (Juniperus monosperma) ; one taken in Texas had filled its 
pouches with the berries of the alligator juniper (Juniperus pachy- 
phloea). In Colorado, according to W. L. Burnett (1918, p. 23), the 
food of rock squirrels of this subspecies "consists of seeds of various 
kinds, apples, cherries, apricots, chokecherries, blackberries, squash, 
and melons. They also eat garden peas, grains of all kinds, and feed 
to some extent on the seed pods of the Yucca and Indian breadroot 
(Psoralea) ." 

Economic status. — The rock squirrels, wherever they come in con- 
tact with agricultural operations, are considered a serious pest. They 
are known to carrj^ off whole ears of corn and to damage all kinds 
of grain. Fruit trees, including peaches, pears, plums, and apricots, 
are visited and the fruit carried off to be eaten or the seeds stored. 

CALIFORNIA GROUND SQUIRREL AND RELATED RACES 

General habits. — Grinnell and Dixon (1918, p. 606) describe the 
habitat of the California ground squirrel (Gitellus beecheyi beecheyi) 
(pi. 8) as follows: 

Its proforences as to local conditions are not closely limited, except that it 
avoids dense chaparral and thick woods. It frequents pasture lands, grain 



24 NORTH AMERICAN FAUNA [No. 56 

fields, orchards, sparsely tree-covered slopes, small mountain meadows, rock 
outcrops on the tops of ridges, and even granite talus slopes. It is always 
most abundant, however, in the open situations, and its decided preferences are 
such that it thickly populates much of the best farming and grazing lands in 
the State, to the great reduction of their producing value from the human 
standpoint. 

Although a true ground squirrel, this species is able to climb trees 
with ease and the animals are often seen in oaks or other nut-bearing 
trees and in fruit trees. 

Burrows and nests. — ^Writing of the animals' burrows, Grinnell 
and Dixon (1918, p. 606) say: 

In shallow adobe or clayey soil, underlain by broken rock, the burrows were 
found to be short, of small diameter, and not reaching to any considerable 
depth. Those in alluvial or sandy soil were found to be of large diameter, 
of greater extent, and to reach to much greater depths. 

The most conspicvious signs of activity on the part of ground squirrels in 
any locality are the large mounds of earth that have accumulated in the course 
of excavating the burrows. This earth is commonly thrown out in a fan- 
shaped pile directly in front of. and to the sides of the main entrance to the 
burrow. These mounds of earth are often 3 or 4 feet in diameter and from 6 
to 10 inches above the general level. 

Seven burrows of this species were excavated by Grinnell and 
Dixon, who report that the shortest occupied burrow was 5 feet in 
length and the longest 138 feet, the average length being 35.2 feet. 
These burrows varied in depth from 18 to 66 inches below the surf ace> 
Three types of burrows are described by them (1918, p. 612) : 

The male squirrels were usually found in short, shallow, simple burrows at 
the outskirts of the "colony." ... It is believed that at least during the 
breeding season the male squirrels live altogether by themselves in their own 
individual burrows. 

The second type was illustrated by a single burrow, 22 feet in 
length and 30 inches deep, containing a female and four young with 
eyes still unopened. This burrow was much more complicated than 
those occupied by the males. 

The third type of burrow might well be called a "colonial burrow", as it is 
used by both sexes and also by the young after these leave the nest burrow 
and begin to forage for themselves. Colonial burrows are used largely as 
"safety zones." They afford convenient places for the squirrels to duck into 
when danger unexpectedly appears. These burrows are often from 100 to 
200 feet in length and form a communicating system of underground runways 
connecting from six to twenty entrances or surface openings. . . . 

Each burrow occupied by a single squirrel was found to contain at least one 
well-made nest. In some cases there were two, one obviously older than the 
other. In the colonial burrow that was dug out, three nests were found, of 
which two were new. The nests were always placed well back in the burrows, 
where they would have maximum protection from digging enemies such as 
coyotes and badgers. The cavities in which the nests were placed were short 
globular chambers and were usually situated slightly above and to one side of 
the main run, so that the drainage was away from rather than into the 
nest. . . . 

All of the nests found were of similar composition and construction. Finely 
shredded dry grass blades and roots, and fine stems of foxtail and needlegrass, 
formed the bulk of the constituent material. The nests were spherical in shape 
and deeply cupped. The walls were from two to two and one-half inches thick 
(1918, p. 615). 

Breeding. — The principal breeding season in the lowlands extends 
from February to the middle of April; at higher altitudes it occurs 
later, even into June. The litters number from 4 to 11, averaging 7.5. 



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In the lowlands thq majority are probably born the last of March, and by 
the last of April the first-born are beginning to appear above ground, playing 
about the mouths of the burrows (1918, p. 620). 

Hibernation. — In these ground squirrels hibernation is not univer- 
sal, and it is not yet known to what extent the animals become dor- 
mant. Over the greater part of their range some individuals may be 
seen abroad most of the year. There are specimens in the Biological 
Survey collection taken at Los Banos, Calif., on January 3 and 4 and 
at Modesto on December 13. Grinnell and Dixon (1918, pp. 631, 632) 
present a table showing that large numbers of the animals were taken 
in January in Contra Costa County, the great majority of which 
were young adults. In their opinion: "It is probable that the full 
old-adult population is not abroad aboveground until the last of 
February." These writers cite an/ instance of a squirrel observed 
closely for a number of years in Pasadena that did not estivate until 
its second year. 

Then and during each succeeding year of its life it estivated regularly, 
becoming very fat and retiring to its burrow during the last week in August. 
It emerged lean and hungry, with marked regularity, about the twenty-second 
of each following February. When removed from the burrow at intervals dur- 
ing this period, the squirrel was found to be in a torpid state, with respira- 
tion not perceptible. 

It seems probable, therefore, in view of this single instance, that a 
certain proportion of adults of this species living in the lowlands 
regularly hibernate. According to Grinnell and Storer (1924, p. 
164)— 

Those individuals which live above the snow line in the mountains hibernate 
for considerable periods during the winter months. In Yosemite Valley, 
ground squirrels in 1920 were first seen out of their burrows about the middle 
of March, according to Mr. Forest S. Townsley. One exceptional individual 
was seen out by one of us, on the Big Oak Flat Road below Geutrys, on 
December 28, 1914. 

Storage of food. — These ground squirrels regularly carry off in 
their cheek pouches various seeds and heads of grain, as well as 
acorns and olives, and store them in their burrows. Writing of this 
habit, Grinnell and Dixon (1918, p. 628)- say: 

In Strawberry Canyon on the University campus, in April, the squirrels were 
harvesting foxtail and alflleria on sunny southern exposures where the plants 
had matured early. Later in the season, during late June and eai'ly July, 
these same squirrels with their families of half-grown young were found to 
have moved down the hillsides, some 150 yards, to the moister, shady ground 
near the creek bed where the foxtail was still green, and here they were busily 
gathering the foxtail heads just ripening on July 6. . . . 

In digging out a colonial burrow near Bakersfield, Kern County, on May 3, 
1918, a storehouse was uncovered. This consisted of a cavity or pocket off the 
main run, which measured five and a half by eight inches in two diameters 
and was eighteen inches beneath the surface of the ground. The stored food 
consisted of a double handful of nearly dry heads of foxtail grass carefully 
packed in dry sand. A few alfileria seeds were also included with the foxtail 
(op. cit. p. 629). 

Merriam (1910, p. 5) writes of the storing habit as follows: 

In Modesto in May 1909, Piper found stores of alfileria seeds packed in cavi- 
ties and well mixed with dry sand. In December of the same year he ex- 
amined a number of stores of grain unearthed by a farmer while scraping and 
leveling his land. Each of these caches consisted of from a pint to a quart of 
oats stored in cavities and packed in dry sand. 



26 NORTH AlVIERICAN FAUNA [No. 56 

Hollister was told by farmers at Aptos that a burrow that had 
been opened in a wheatfield was found to contain 3 pecks of shelled 
wheat. 

Food habits. — The California ground squirrel feeds on a great 
variety of seeds, nuts, fruits, and green herbage. Merriam (1910, p. 
4) states — 

Acorns are a favorite food and where obtainable are gathered and stored in 
large quantities. The same is true of nianroot (Echinocystis fahacea), the 
seeds of which are eagerly eaten, according to Piper, from the time they 
begin to form until fully ripe. At Modesto the squirrels were eating them as 
early as the middle of May and as late as the middle of December. Other 
favorite seeds are those of elderberry (Samiucus) , jimson vs^eed (Datura), 
wild nightshade (Solanum), turkey mullein (Eremocarpus) , tarweed (Madia), 
and numerous grasses. Of cultivated nuts, almonds and walnuts are preferred ; 
of other crops, apples, prunes, peaches, apricots, figs, olives, certain garden vege- 
tables, the seeds of cantaloupes, watermelons, and citron melons, and all the 
grains are eaten wherever they are to be had, and green alfalfa and clover are 
sometimes taken. In November — sometimes earlier, according to the date on 
which the early rains begin — tender green vegetation becomes abundant, and 
the ground squirrels turn their attention to it. At this season their chief food 
consists of green stuff, mainly young wild oats and filaree, the latter a small 
member of the geranium family widely distributed in California and valued as 
a forage plant. In several localities in March the cheek pouches of animals 
examined by Piper were filled with the yet green seeds of filaree. In June the 
pouches are often filled with alfalfa leaves and flowers. In southern Cali- 
fijrnia the squirrels are fond of the fruit of the prickly pear (Opuntia). 

Grinnell and Dixon (1918, p, 628) say that on wild land, alfileria, 
foxtail, and bur-clover are perhaps the three forage plants that are 
eaten to a greater extent than any others. 

The same authors (p. 626) mention a ground squirrel taken at 
Cisco in October that was carrying in its pouches 92 seeds of the 
green manzanita (Arctostaphylos patula) and another taken in Mari- 
posa County that had dug up and was carrying in its pouches 12 
bulbs of a species of wild-hyacinth (Brodiaea hyacinthina) . 

Economic status. — It may be seen from statements in the life 
liistory of this species that the California ground squirrel is capable 
of great injury to agriculture. In California, where it is considered 
to be the most important of the rodent pests, large sums of money are 
expended in efforts to control its depredations. In addition to the 
damage inflicted on crops of grain, forage, fruits, and nuts, the ani- 
mals are reported to destroy young chickens. 

In recent years this species has been found to be a carrier of both 
bubonic plague and tularemia. Plague appeared in California in 
1900 and shortly thereafter it was found to be present in these ground 
squirrels. Dr. W. H. Kellogg (1935, p. 856), writing of the plague 
in California, said : 

Infected squirrels [Citellus beeclieyi] were found in 1908, and plague has 
been enzootic among the squirrels of California ever since. At that time an 
acute and very severe epizootic ensued, the number of plague-infected squirrels 
picked up in that county [Contra Costa] being over 1,700 during the few years 
following 1908. This epizootic extended in the neighboring counties of the Bay 
area and it was accompanied by a human epidemic in San Francisco and Oak- 
land, the number of cases between May 1907 and June 30, 1908, when the last 
case of this second epidemic of human plague occurred, being 160 and the 
number of deaths 77. 

Eradicative measures were carried on jointly by the Public Health 
Service and the State Health Department from 1908 to 1912, covering 



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most of California and parts of adjacent States, and at the end of 
that campaign it was thought that danger of further spread of the 
plague had been removed. In the spring of 1934, however, fresh out- 
breaks of plague were discovered in Kern and Tulare Counties, and 
as a result of exterminative measures carried on in these counties 
from March to July, 5,973 squirrels were shot and 2,853 found dead, 
and of those sent to the laboratory, 118 were reported to be infected. 
The number of plague foci located was 41 over an area of approxi- 
mately 896 square miles. 

Tularemia was discovered in the California ground squirrel by 
Surgeon George W. McCoy in 1910 (1911, p. 53) while searching for 
league in this rodent. According to Francis (1937, p. 106), hovv- 
ever, human cases of tularemia have not as yet been traced to this 
animal. 

DOUGLAS'S GROUND SQUIRREL 

General habits. — The habits of Douglas's ground squirrel {Citellus 
heecheyi douglasii) (pi. 8) in California are described by Grmnell 
and Dixon (1918, p. 646) as follows: 

The local or habitat preference of this species is more exclusively for hilly 
country than in the case of the California ground squirrel. It is true that the 
Douglas exists out on the floor of the Sacramento Valley nearly to the lands 
annually flooded along the river ; but it occurs there interruptedly, in far sepa- 
rated "colonies", and never anywhere are the great numbers reached that char- 
acterize heecheyi in the San Joaquin Valley. The preferred haunts of douglasii 
are the openings or glades on hillsides, beneath scattered oaks or pines, or else 
the open tracts along stream courses, not, however, quite down to the water's 
edge. The edges of the smaller valleys between the coast ranges are well 
populated, but the open floors of these valleys are not often invaded very far or 
in any considerable numbers. Dense chaparral and thick woods are avoided 
altogether. . . . Steep banks seem to be cho.seu for burrowing into, whenever 
available. Many burrows open under rocks, bushes, and tree roots. On open, 
level ground, with no protective shelter at hand, the mouths of the burrows are 
marked by good-sized mounds, showing the presence of an extensive system 
below ground. As far as we know, no one has yet made a complete excavation 
of the burrow system of this species. 

Douglas's squirrel is reported to climb trees more frequently than 
the other members of the heecheyi group, and there are instances of 
individuals having been seen as high as 30 to 60 feet above the 
ground. 

The alarm call of this species, according to Vernon Bailey, is — 

a series of rasping squeaks with a rising inflection, somewhat like the cry of 
Ochotona. It is neither a whistle nor a chipper, but sounds like an attempted 
bark with something loose in the animal's throat. 

Merriam mentions an individual that uttered "a shrill whistle of sur- 
prising loudness and penetration, suggesting the alarm note of the 
marmots." 

Hibernation apparently is more prevalent in this subspecies than 
in any otlier races of heecheyi; at high altitudes the animals are re- 
ported to disappear completely for a period of 6 to 8 weeks in mid- 
winter. In the Sacramento Valley, at Chico and St. John, however, 
they were found out of their burrows on sunny days in winter and 
6 specimens were taken there on January 4 and 6, 1906. 

The young are brought forth during May in the lowlands, prob- 
ably later in the mountains. Two specimens taken at Lower Lake, 
Calif., April 23, contained, respectively, five and six embryos; one 



28 NORTH AMERICAN FAUNA [No. 56 

taken at Slierwood, Calif., May 5, contained seven embryos ; one from 
Eel River, May 18, contained five; and one from Cliico, May 20, 
contained five, nearly ready for birth. 

Food habits. — The food of this ground squirrel consists largely of 
the seeds and fruits of a variety of wild plants, with the addition of 
cultivated grain and some insects (grasshoppers). The plant food 
recorded by the field collectors of the Biological Survey as found in 
the cheek pouches of these squirrels is as follows: Acorns, chin- 
quapins, nuts of the California buckeye {Aesculus calif ornica) and 
the California-laurel {Umhellularia calif ornica)^ maple seeds, berries 
of skunkbush {Rhus trilohata), camas bulbs, seeds of California bur- 
clover {Medicago hispida), alfileria, and bitterbrush {Purshia tri- 
dentata)^ wild oats, and wheat. Grinnell and Dixon (1918, p. 648) 
list the following items found in cheek pouches of this species; 29 
seeds of a wild lupine {Lupinus micranthus) ; 12 seeds of milkthistle 
{Silyhum marianum) ; 219 grains of barley and one head of buck- 
horn plantain {Plantago lanceolata) ; 121 seeds of bur-clover {Medi- 
cago hispida) ; 181 seeds of California brome {Bromus carinatus) 
and a piece of an acorn; 29 seeds of Malta star-thistle {Gentaurea 
melitensis) and 30 seeds of bur-clover; 14 whole fruits and 103 sepa- 
rate seeds of the common manzanita {Arctostaphylos inanzanita) . 

Economic status. — Douglas's squirrel apparently is less prolific and 
never reaches the extreme abundance of the subspecies heecheyi and 
flsheri. Locally, however, the animals prove destructive to crops of 
wheat and barley and to the almond crop ; Grimiell and Dixon (1918, 
p. 648) state that the squirrels have been known to invade apricot 
orchards, where they climb the trees and take out the apricot pits, 
discarding the fruit pulp. 

RING-TAILED AND GOLDMAN'S GROUND SQUIRRELS 

General habits. — In their notes on Biological Survey field work, 
Nelson and Goldman write of the habits of the ring-tailed and Gold- 
man's ground squirrels {Citellus annulatus subspp.) (pi. 9) as 
observed in Colima, Mexico, as follows : 

On the flat country about Armeria they are excessively common and in this 
locality one could have shot 20 in a morning. As a rule they are not shy 
although many will rush into their burrows at first glimpse of an intruder. We 
found their burrows on hillsides, among the rocks ; and again in the sandy 
flats, along walls and hedges bordering cultivated fields; they are equally at 
home in the silent and gloomy shade of the densest groves of oil palms, with a 
burrow under a mass of fallen palm fronds or sheltered by the thorny growth 
of mesquite and acacia. Again their burrows are found under a cactus whose 
spreading branches give safe shelter on more open ground. The nuts of the 
oil palm, mesquite beans, cactus seeds and the fleshy fronds of the pear- 
leaved cactus, wild figs, moho nuts, and a variety of other seeds and fruits 
make up their varied bill of fare. In going silently along the trails leading 
through the dense palm groves and thickets of other trees, where the "tezmo" 
lives, they may be seen gliding silently from log to log or from one bunch of 
brush or similar shelter to another, now stopping a moment to dig for a seed 
or sitting up on their haunches to eat some morsel and then on again. They are 
often seen 10 or 12 feet up on the trunk of a small tree — sometimes out on the 
ends of branches after mesquite beans, cactus leaves, or other fruit — and when 
surprised they frequently run up a tree a few feet, take a hasty look at the 
intruder, then around the tree, down the other side and away in a direct line, 
so that before one knows it he may see his expected prey whisk into a brush pile 
or hole many yards away. Often they will crouch close to the ground and lie 
very still in the bushes so that they are only seen by accident, whUe others will 



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1938] REVISION OF THE GROUND SQUIRRELS 29 

steal softly away to some sheltering hole and thence utter short, shrill, whis- 
tling or chirping notes at short intervals. This is the only note we have heard 
them give. When their curiosity is aroused they will draw near, stopping to 
stand up on their hind feet, sometimes stretching the body up so that the tail 
is used to help support the body as on a tripod. At the first alarm they scurry 
away into the first shelter. They carry their tails in a curve quite squirrel-like 
in character and their motions are more light and agile than those of most 
spermophiles. 

LESSER TROPICAL GROUND SQUIRREL 

General habits. — The habits of the lesser tropical ground squirrel 
{Citellus adocetus) are described in the field notes of Nelson and 
Goldman as follows: 

They live among rocks along canyon sides, about stone walls and corrals 
near ranches, and sometimes their burrows are located in open ground at the 
base of a tree or bush. They are seen running about at all hours of the day, 
but are most active from 9 to 11 in the morning. Near ranch houses they 
become quite tame and often approach to within a few feet of the doors after 
scraps of food thrown out by the people. In the fields and scattered woods 
where they occur they are rather shy and retreat to their holes at the first 
sight of a person or other cause of alarm. 

They were abundant about the ranch near La Huacana rMichoacan] and 
especiall.v numerous along the stone walls bordering the trail near the ranch 
of Agua Blanca and in the old lava beds extending away from the south base 
of the volcano of Jorullo. We left Agua Blanca early in the morning with 
the sun just becoming warm, and dozens of these little animals were seen 
scampering along the trail ahead of us, sometimes playfully pursuing one 
another or sitting up to look about. As we drew near they ran to the stone 
walls and either sat on the top or took refuge in the crevices and with heads 
projecting from the holes watched us pass. Now and then one scurried away 
to a hole under a stone or at the foot of a tree or bush. Their habits here 
w^ere remarkably like those of Citellus annulatus aloug the stone-walled roads 
near the city of Colima. The present species has a sharp chirping call note. 
At the ranch near La Huacana they were living mainly in holes under rocks 
or bushes, but some also in stone walls. Wherever they are located along 
roads they have become accustomed to people and are less shy than in more 
unfrequented places. 

ANTELOPE GROUND SQUIRRELS 

General habits. — The antelope ground squirrels (subgenus Am- 
mospermophilus) (pi. 10) live chiefly in Sonoran Zone deserts, 
occupying open country among bushes and clumps of cactus and 
showing a preference for more or less rocky situations. They dig 
shallow burrows under bushes or among rocks and apparently use 
also the burrows of other animals, especially those of the large kan- 
garoo rats {Dipodomys) . They apparently do not hibernate, but 
during severe weather may remain for long periods within their 
burrows. E. R. Sans says he has seen them out on top of a foot of 
snow. They are active, nervous, and very wary creatures, and when 
alarmed run rapidly to cover with their tails held straight up or 
curled over their backs. They are good climbers and are often seen 
sitting in a bush or clump of cactus, several feet alcove the ground. 
Their notes are described as "a shrill, rapid chipper." The youn^, 
numbering usually 6 to 9, or occasionally 12, are brought forth in 
March or April. 

Food habits. — The food of the antelope squirrels consists chiefly 
of the seeds or berries of a large variety of desert shrubs. The 
fleshy fruit and the seeds of various species of cactus are frequently 
eaten, as are also seeds of mesquite, huisache [Acacia farnesiana), 



30 NORTH AMERICAN FAUNA [No. 56 

yucca, palo verde {Cercidium fioriduin)^ ocotillo {Fouquieria splen- 
dens), sotol {Dasylirion texanum), saltbush (Atriplex), Kussian- 
thistle, skunkbush (Rhus ti^ilohata) , greasewooa {Sarcobatus)^ sun- 
flower, wild plum, and single leaf pinyon (Pinus monophylla) . 
Small numbers of insects have been found in tlie animals' pouches. 

A specimen taken at Kesting Springs, Calif., February 9, 1891, 
had 46 grains of barley in its cheek pouches. 

Economic status. — ^Living chiefly in desert regions, the antelope 
squirrels do not often come in contact with cultivated crops; but 
Bometimes in irrigated valleys they are attracted to grainfields and 
gardens and in such cases may cause damage by destroying ripening 
grain or planted seeds of melons or corn. 

MOHAVE GROUND SQUIRREL 

General habits. — Burt (1936, p. 221) has given an account of the 
habits of the Mohave ground squirrel {Oitellus mohavensis) based 
on a study made at Palmdale, Calif., in the spring of 1931. From 
this account, the following facts are selected. 

The animals live on the lower desert, preferring areas where the 
soil is sandy or of sand mixed with gravel, and where there is a 
sparse growth of sagebrush. Their burrows enter the ground at 
an angle of about 35° ; one examined was a simple tunnel 54 inches 
in length, 12 inches below the surface at its deepest point, with two 
entrance holes 2 to 2i/2 inches in diameter. Some of the burrows 
had been partially plugged with earth after the entrance of the 
animal. 

The squirrels rarely run rapidly for any distance, and when danger 
threatens they dodge into a hole or sometimes crouch low on their 
bellies and remain quiet. When running the tail is carried over the 
back, after the manner of Ammospermophllus, but is not twitched. 
If slightly startled the animals rise upon their hind feet — "picket- 
pin" fashion — with the front legs hanging limply. 

A squirrel observed for 50 minutes on April 12 fed in a patch of 
green vegetation, chiefly alfileria; occasionally it climbed into small 
bushes to a height of about a foot and ate some green buds. 

Its call "resembles a shrill whistle. It is a high pitched peep, 
with a slight rasping effect." 

A female taken March 29 contained six embryos ; one taken April 
12 was suckling young. 

ROUND-TAILED GROUND SQUIRRELS 

General habits. — The round-tailed ground squirrels [Oitellus tere- 
tioaudus subspp.) are typical desert animals, living in the hottest 
parts of the Lower Sonoran Zone in southern California and Ari- 
zona. They occur in more or less isolated colonies in mellow, sandy 
soil. Grinnell and Dixon (1918, p. 669) say that these ground 
squirrels prefer areas where wind-drifted sand has been accumu- 
lated into mounds about the bases of mesquite, creosote, or saltbushes. 
They make use of the burrows of other rodents, particularly kan- 
garoo rats, but sometimes they dig burrows for themselves in the 
sandy flats or in the banks of a gulch or dike. These burrows may 
be 5 or 6 feet in length and reach a depth of 2 to 3 feet. Several 
examined by Vernon Bailey contained nests of grass at the lower end. 



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Living in a mild climate, these squirrels apparently do not hiber- 
nate completely, but they are rarely seen on cold or cloudy days dur- 
ing the winter season and may remain in their burrows for somewhat 
extended periods. At Fort Lowell, Ariz., in midwinter, A. Brazier 
Howell noted them out only about once a week until January 24, 
after which they became abundant. Early in February the females 
ventured out infrequently and appeared ragged, but the males were 
in good pelage. Near Tucson, Ariz., the first were seen out of their 
burrows on January 27. A specimen was taken at Needles, Calif., 
December 12, and one at Agua Caliente on January 15. 

Although chiefly ground dwellers, these squirrels occasionally 
climb into bushes in search of food or to survey the surrounding 
country. Swarth (1929, p. 349) mentions seeing one 10 feet or more 
up in a mesquite tree. Their voice is described by Vernon Bailey as 
a fine shrill whistle, so thin and sharp that it sounds like the note of 
an insect. He says that there is no vibration or trill to it, as in the 
voice of the members of the spilosoma or the tridecemlineatus groups, 
but that it is often prolonged and evenly sustained. 

The young are brought forth in March and April and there may 
be a second litter later in the season. Two specimens taken in Death 
Valley, Calif., April 7, contained six and seven embryos, respectively. 
Three taken at Fort Mohave, Ariz., March 11 and 12, contained 10, 
11, and 12, respectively. One taken at Ivanpah, Calif., June 2, con- 
tained eight. 

Food habits. — Stephens (1906, p. 70) says of this species: 

The food is seeds the greater part of the year; these are stored to some 
extent. In the spring, during the few weeks when green vegetation is obtain- 
able, leaves and buds are eaten voraciously. 

Grinnell and Dixon (1918, p. 671) state that stems of the "squaw- 
tea" or jointfir {Ephedra) and leaves of the mesquite form an im- 
portant element of the diet wherever and whenever obtainable. They 
state, also, on the authority of W. C. Jacobsen, that in the Imperial 
Valley these squirrels were known to invade alfalfa fields and to eat 
the alfalfa leaves, discarding the stems. 

Among the food elements recorded in the stomachs or cheek 
pouches of this species are cactus fruit, blossoms of ocotillo {Fou- 
quieria splendens), mesquite beans and leaves, seeds of plantain 
{Plantago) and of goosefoot {Chenopodium) ^ wheat, barley, and 
small insects. 

Living mainly in desert areas, these squirrels rarely come in con- 
tact with agricultural crops and they are therefore of little economic 
importance. 

MANTLED GROUND SQUIRRELS 

General habits. — The mantled ground squirrels (subgenus Callo- 
f>permophilus) (pi. 11) inhabit mountain slopes and foothills, living 
in the more open forested country among rocks and fallen timber. 
Their burrows are dug usually under rocks or stamps, and the ani- 
mals spend much time resting quietly on some rock or log in the sun- 
shine. They occasionally climb into bushes or trees to a height of 20 
or 30 feet m search of food, but their ordinary habitat is on the 
ground. They are of rather sluggish movements and when running, 
elevate the tail at an angle of about 45°. Ordinarily they are silent. 



32 NORTH AMERICAN FAUNA [No. 56 

but Bailey says that on occasions tliey utter a clear, birdlike whistle, 
very shrill and piercing, entirely unlike the note of the chipmunks. 
When gathering food supplies, they often pack their capacious 
cheek pouches so full that their cheeks stand out as in a case of the 
mumps. In fall they store food in underground chambers. 

Hibernation. — These squirrels become very fat early in fall and by 
the middle of September most of them have retired underground 
for their winter's sleep; a few, however, may be found out of their 
burrows in October or November (Lake Tahoe, Calif., Oct. 6; Tula- 
rosa Mountains, N. Mex., Oct. 12 ; Mogollon Mountains, N. Mex., Oct. 
28; Pikes Peak, Colo., Nov. 2 (Hatt, 1927, p. 19) ). In the Bitterroot 
Valley, Mont., the first one seen in spring was on March 28 (1910) 
and by April 10 they were observed in numbers. In milder climates 
they may come out of hibernation earlier than this. Females carry- 
ing four to six or rarely eight embryos are recorded during May, 
June, and July. 

Burrows and nests. — Hatt (1927, p. 8) describes a burrow examined 
in Douglas County, Colo., as follows : 

The diametei' of the burrow at the entrance was 3 inches. For the distance 
of a foot there was a 45° angle and then the course flattened out to a depth 
uniformly 8 inches under the surface, except at the opposite end and in one 
of the pockets. A few inches past the entrance the tunnel narrowed down to a 
uniform 2-inch bore. At one place in its course the roof was crossed by the 
root of an aspen. Farther on the tunnel passed directly under the base of a 
tree and beneath its roots. 

The first pocket leading from the main passage contained no debris of any 
sort, and at the time of the excavation could not have been in use unless it 
was a passing place or unlined nesting site. 

Six feet in from the entrance the passage forked, one lead passing directly 
to the nest, the other passing to it by a semicircular arc. A runway surrounded 
the nest on three sides, from which there were four passages leading in. This 
nest cavity was 4 inches deep, the nest not filling the space available, but 
occurring more as a mat in the bottom of the cup. 

A passage led away from the nest in the direction opposite from that of the 
other main passage. Six inches from the cavity this forked, one branch lead- 
ing from an empty chamber 5% inches in diameter, beyond which was a blind 
lead filled for a distance of about 12 inches with old nesting material, firmly 
packed. The other branch led by an angular path and a sharp grade to another 
entrance completely obscured by kinnikinnik and hidden by a mat of leaves. 

Food hatits. — The food of the mantled ground squirrels is chiefly 
of vegetable origin and comprises a large variety of the seeds and 
berries of wild plants, including acorns and seeds of yellow pine 
and Douglas fir, small wild beans, serviceberries (Amelanchier) , 
gooseberries (Grossularm irrigua), currants, thimbleberries, and the 
seeds of roses, lupine, puccoon {Lithosipermum) ., alfileria, clover, 
Polygonum, shepherds-purse (Ca'pseUa) ., milkvetch {Astragalus) ., 
false-indigo {Am.morpha calif ornica) ., willowweed (Epilohium), 
beardtongue {Penfsteinon), bitterbrush (Purshia tridentata) ., gilia, 
and greengentian (Frasera). One squirrel captured had 410 weed 
seeds in its pouches : another had taken 360 grains of barley, gatliered 
along a road. Mushrooms are frequently eaten, as also are grass- 
hoppers, beetles, caterpillars, ants, flies, and various other insects. 
Hatt (1927, p. 12) reports seeing one of these squirrels feeding on 
the fruits of stickleaf {Menfselia nnuXtif,ora) . Vernon Bailey ex- 
amined a specimen in Oregon that had filled its cheek pouches to 
their limit with ripe seeds of the Nuttall violet {Viola nuttallil). 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 11 




1938] REVISION OF THE GROUND SQUIRRELS 33 

Economic status. — ^Living as they do chiefly in mountainous and 
unsettled areas, these squirrels rarely come in contact with civiliza- 
tion. In certain valleys, however, they at times forage in grain- 
fields and destroy considerable quantities of wheat, oats, or barley. 
Around hunters' or miners' camps they are often attracted by stores 
of food and unless means are taken to keep them out they will per- 
sistently carry off any food materials that appeal to their taste. 



in4970 — 38- 



CLASSIFICATION OF THE NORTH AMERICAN SCIURIDAE 

In connection with the present revision of the North American 
ground squirrels, it seemed desirable to make a critical study of all 
the North American members of the family Sciuridae, in an effort 
to devise a classification in which the generic and subgeneric groups 
can be based on the most constant and deep-seated skeletal charac- 
ters. This has proved to be a task of considerable difficulty, for 
although the various groups commonly recognized are easily sep- 
arable by external characters, critical study of their cranial and 
dental characters (pi. 12) reveals in many cases close relationship 
among a number of groups, shown by extensive gradation from one 
to another in supposedly diagnostic characters.^ 

The lack of agreement among zoologists as to what characters 
should be used to characterize a genus results in great diversity of 
treatment by systematic workers and consequent confusion of the 
laymen, who are naturally less interested in questions of relationship 
than in stability of the names they are called upon to use. 

A genus is sometimes a natural group, but is often merely a concept 
in the mind of the systematist by which certain related species are 
associated under a single generic name. The limits of a particular 
genus, therefore, may be subject to change at the will of any 
reviser, as his viewpoint with reference to generic characters changes, 
or as new facts or new species come to his attention. This situation 
is well illustrated by the evolution of the generic concept in the 
mind of one of our most distinguished American zoologists, the late 
J. A. Allen. In his monograph of the Sciuridae, published in 1877, 
he recognized a single genus — Sciurus — for all the tree squirrels of 
North America and South America. The five outstanding groups of 
North America were treated as species (some with several varieties) 
and nine additional species were recognized from Middle America 
and South America. In his last paper on the squirrels, published 
38 years later (1915), working, of course, with a vastly increased 
quantity of material, he recognized eight genera from North America 
and nine additional genera from South America. Each of the five 
North American species recognized in 1877 was in 1915 given full 
generic rank — Tamiasciurus for the red squirrels; NeosGiwrus for 
the eastern gray squirrel; Otosciurus for Abert's squirrel of the 
Southwest ; H esperosciurus for the western gray squirrel ; and Para- 
seiurus for the fox squirrels. 

The same tendency to give generic rank to practically every recog- 
nizable group is more or less prevalent today among workers in 
other branches of zoology. Such a course results in our so-called 
genera becoming little more than specific groups. The purpose of 

' In this study the writer has had the advice and assistance of Gerrit S. Miller, Jr., 
curator of mammals, U. S. National Museum, who generously turned over a partially com- 
pleted key to the genera of ground squirrels and related groups and also checked with the 
author the cranial characters of the various groups. 

34 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 12 




UPPER AND LOWER MOLARIFORM TOOTH ROWS OF CYNOMYS LUDOVICI ANUS. 

(Kiilarged about diameters.) 



pa = paracone. 
TOC = inetac()ne. 
pr = i)rotoc()iie. 



parf = paraconi(i. 
fn/ = ent()coni<i. 
prii= protocoiiiil. 



/i;/r/ = hyp()Coni(l 
/)«.s = parastyle. 
;».■( = mesostyle. 



7K/« = ineta.style. 
/)r/ = protolopli. 
;H7/-inetalopli. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 13 





/ 




K L 



a 




W 



BACULA OF VARIOUS SCIURIDAE. 

(Enlarged about 5}i diameters — see explanation on facing page.) 



1938] 



REVISION OF THE GROUND SQUIRRELS 



35 



systematic nomenclature should be to show not only that there are 
diff ereTices between the various forms but also that there are resem- 
blances that indicate relationship. Giving a generic name to every 
recognizable group emphasizes the differences between related 
groups but fails entirely to show their similarities. 

A more reasonable and satisfactory classification will be attained 
by recognizing as subgenera groups that are distinguished by cranial 
characters of minor importance, or that show gradation in cranial 
or dental characters from one group to another. This treatment 
should be satisfactory both to the layman and to the systematist. 
One who is interested chiefly in having a definite and permanent 
name to use for every species may disregard the subgeneric name 
entirely, while the technical worker who desires to show the rela- 
tionship of the various groups can do so by the use of both generic 
and subgeneric names. 

Examination of the baculum (pi, 13), or penis bone, in a small 
number of individuals representing most of the subgeneric groups 
shows that this bone has characters that are of assistance in defining 
the groups. The writer does not believe, however, that in the ab- 
sence of trenchant cranial characters, the morphology of the baculum 
alone should be considered of generic value. 

The North American Sciuridae may be roughly divided into four 
groups, as follows: 

1. The marmots {Marmota)^ prairie dogs {Cynomys)^ and ground 
squirrels {Oitellus), including the rock squirrels (Otospermopkilus) , 
mantled ground squirrels {Callospermophilus)^ and antelope squir- 
rels (Ammospermophilus) , which three heretofore have been treated 
by some writers as genera. 

2. The chipmunks (Tamias and Eutamias) . 

3. The tree squirrels (Sciurus, Tamiasciurus, Microsciurus. and 
Syntheosciu7-us) . 

4. The flying squirrels {Glaucomys). 



Explanation of Plate 13 
(Enlarged about 3H diameters) 



A. Tamias striatus. 

B. Tamias striatus. 
Eutamias (Eutamias) asiaticus. 
Eutamias (Neotamias) townsendii 

sonomae. 
Eutamias (Neotamias) quadrivitta- 

tus frater. 
Eutamias (Neotamias) cinereicollis. 
Citellus (Otospermophilus) varie- 

gatus grammurus. 
H. Citellus (Otospermophilus) variega- 

tus grammurus. 
Citellus (Otospermophilus) variega- 

tus buckleyi. 
Citellus (Cailospermophilus) later- 
alis. 
Citellus (Ammospermophilus) har- 

risii. 



L. Citellus (Ammospermophilus) har- 

risii. 
M. Cynomys (Cynomys) ludovicianus. 
A^ Citellus (Ictidomys) tridecemline- 

atus. 
0. Citellus (Ictidomys) mexicanus. 
P. Citellus (Poliocitellus) franklinii. 
Q. Citellus (Citellus) beldingi oregonus. 
R. Citellus (Xerospermophilus) tereti- 

caudus. 
S. Sciurus (Neosciurus) carolinensis. 
T. Sciurus (Neosciurus) variegatoides 

dorsalis. 
U. Sciurus (Parasciurus) niger limitis. 
V. Sciurus (Hesperosciurus) griseus. 
W. Sciurus (Otosciurus) aberti. 
X. Glaucomys volans. 



3g NORTH AMERICAN FAUNA [No. 56 

The marmots, prairie dogs, and ground squirrels are all closely 
related. In comparison with the tree squirrels they are character- 
ized in general by a shallower brain case; narrower interorbital 
region ; more wide-spreading zygomata, which are usually not paral- 
lel but contracted anteriorly and twisted in the jugal region from a 
vertical toward a horizontal plane; the upper surface of the jugal 
is without an angular process; the antorbital foramen is broader 
(either subtriangular or oval) ; the molars are usually more hypso- 
dont and the crown pattern more complicated; and the anterior 
upper premolar (pm^) is always present and often of relatively 
large size. This tooth is of varying size in the different groups of 
ground squirrels and furnishes a character useful in distinguishing 
the subgenera. 

Key to Genera and Subgeneea 

a^. No antorbital canal, the antorbital foramen piercing the zygo- 
matic plate of the maxillary. 

6\ Premolars f Genus Tamias (p. 46) 

1)\ Premolars ^ Genus Eutamias (p. 47) 

c\ Antorbital foramen large, suborbicular Subgenus Eutamias (p. 47) 

cl Antorbital foramen smaller, narrowly oval- Subgenus Neotamias (p. 47) 
o^ Antorbital canal present. 

6\ Anterior lower premolar bearing a paraconulid Genus Makmota (p. 37) 

c\ Pollex suppressed Subgenus Mabmota (p. 38) 

c^ Pollex present Subgenus Maemotops (p. 38) 

6^ Anterior lower premolar without a paraconulid. 

c\ Zygomata not parallel, but contracted anteriorly, and an- 
terior portion twisted toward a horizontal plane 
(groimd squirrels and prairie dogs). 
d\ Upper molar rows strongly convergent 

posteriorly Genus Cynomys (p. 38) 

e\ Jugal thickened anteriorly Subgenus Cynomys (p. 38) 

e". Jugal not thickened anteriorly. Subgenus Leucocrossukomys (p. 38) 
d^. Upper molar rows not strongly convergent 

posteriorly Genus Citeulus (p. 39) 

e\ Molars relatively hypsodont ; parastyle ridge on m^ 
and m^ joining protocone with an abrupt change of 
direction. 

f. Metaloph on pm* continuous Subgenus Citellus (p. 40) 

f. Metaloph on pm* not continuous Subgenus Ictidomys (p. 41) 

e". Molars relatively brachydont; parastyle ridge on m^ 
and m° rising evenly to join the protocone, without 
abrupt change of direction. 
f-. Anterior upper premolar simple ; less than one- 
fourth the size of pm^. 
g^. Upper incisors relatively stout and distinctly re- 
curved. 
li^. Brain case rounded on upper surface. 
t\ Supraorbital foramen 

open Subgenus Otospebmophilus (p. 43) 

f. Supraorbital foramen 

closed Subgenus Notociteixus (p. 44) 

}f. Brain case flattened on upper 

surface Subgenus Ammospeemophilus (p. 44) 

g^. Upper incisors relatively slender— not distinctly 
recurved. 
7i-\ Postorbital processes long and slender; rostrum 

longer Subgenus Caixospermophixus (p. 4.5) 

h^. Postorbital processes short and stout; rostrum 

shorter Subgenus Xerospeemophilus (p. 45) 

f. Anterior upper premolar more than one-fourth the 
size of pm^, showing two cusps or a functional 
cutting edge Subgenus Poliociteixus (p. 42) 



1938] REVISION OF THE GROUND SQUIRRELS 37 

c^ Zygomata nearly parallel (little if any contracted ante- 
riorly) and nearly vertical — not twisted (tree squirrels). 
d\ Interorbital region relatively narrow and deeply 

notched Genus Glaucomys (p. 52) 

d^. Interorbital region relatively broad and not deeply 
notched. 
e^. Upper incisors projecting forward (to or beyond plane 
of tip of nasals). 

f. Upper incisors grooved Genus Syntheoscixirus (p. 52) 

f. Upper incisors not grooved Genus Microsciueus (p. 51) 

e■^ Upper incisors not projecting forward Genus Sciukus (p. 48) 

f. Premolars r- 

f/\ Notch in zygomatic plate of maxillary opposite 

m} Subgenus Parasciurus (p. 50) 

g^. Notch in zygomatic plate of maxillary opposite 
pni* (or sometimes the division between pm* and 

m^) Subgenus Guerlinguetus (p. 50) 

f. Premolars y. 

g^. Notch in zygomatic plate of maxillary opposite 
pni.* 
7i,\ Anterior upper premolar (pw') well developed; 

baculum present Subgenus SciURUS (p. 48) 

h^. Anterior upper premolar (pm^) vestigial — often 

absent; baculum absent Genus Tamiasciueus (p. 51) 

.9^ Notch in zygomatic plate of maxillary opposite m\ 
h\ Second upper premolar {pni*) broader than 

long Subgenus Hesperosciueus (p. 49) 

h^. Second upper premolar {pm*) not broader than 
long. 
i^. Interorbital breadth greater than postorbital 

breadth Subgenus Otosciurus (p. 50) 

f. Interorbital breadth not greater than post- 
orbital breadth Subgenus Neosciueus (p. 48) 

Genus MARMOTA: Marmots 

Martnota Blumenbach, Handbuch der Naturgeschichte 1: 70, 1779 (type, Mus 
marmota Linnaeus). 

The marmots, woodchucks, or ground hogs attain the largest size 
of any of the Sciuridae. The skull is nearly flat on top, the tip of 
the rostrum slightly depressed ; the brain case is very broad, the zygo- 
matic arches wide-spreading, their anterior portion thickened; 
the postorbital processes are very broad, not greatly depressed, pro- 
jecting nearly at right angles to the axis of the skull at about the 
middle portion of the orbit. 

The upper molars are heavy, subquadrate, and brachydont, with 
heightened inner cones; the anterior upper premolar is about one- 
third as large as pm'^; pm* is about as long as broad, or slightly 
longer, with a prominent parastyle separated from the protoloph by a 
broad valley; the parastyle ridge on m^ and m^ is low and joins the 
protocone with an abrupt change of direction ; the metaloph on pm'^, 
m^, and m^ is more or less interrupted; on m^ it turns backward to 
join the heel. The lower molars are heavy, with prominent cones 
and deep valleys; on the anterior lower premolar the protoconid 
and paraconid are separated by a broad sulcus, and there are one or 
two small cusplets on the anterior face of the tooth between the two 
principal cusps. 

The upper incisors are heavy, and less compressed laterally than 
in Citellus, their anterior face smoothly rounded. 



38 



NORTH AMERICAN FAUNA tNo. 56 



Subgenus MARMOTA 

Pocock (1923a, p. 1200) has divided the genus Marmota on the 
presence or absence of the pollex. The type species— J/, marmota^ 
of Europe — apparently differs from all the other species in the com- 
plete absence of this digit. Comparison of the skulls of M. marraota 
and M. monax shows no distinguishing characters of more than 
specific value. 

Subgenus MARMOTOPS 

Marmotops Pocook, Zool. Soc. London Proc. 1922: 1200, 1923 (type, Marmota 
monax) . 

As shown by Pocock and verified by examination of specimens in 
the United States National Museum, all the American and Eurasian 
species except M. marmota possess a rudimentary thumb (pollex) 
bearing a broad, flat nail. This character is considered to be of sub- 
jreneric value. 

Genus CYNOMYS: Prairie Dogs 

Cynomys Rafinesque, Amer. Monthly Mag. 2: 45, 1817 (type, Cynomys socialis 
Rafinesque = C. ludovicianus) . 

The prairie dogs are more closely related to the ground squirrels 
{Citellus) than to the marmots. The skull of Cynomys resembles 
that of Citellus parryii rather closely in general contour, but differs 
in several important characters. The molariform teeth are very 
heavy, much broader than long, high crowned on inner side ; the inner 
roots of m^ and m^ are greatly enlarged and the outer roots corre- 
spondingly reduced; the upper tooth rows are strongly convergent 
posteriorly, instead of being nearly parallel as in Marmota and Citel- 
lus. The anterior premolar is always very large — more than half the 
size of pm* — its outline oval rather than subcircular. The trans- 
verse ridges on m^ and m"^ are more crowded than in Citellus^ with a 
relatively shallow valley between ; on the last upper molar the crown 
pattern is more complicated, having two complete transverse ridges 
and an additional ridge extending from the mesostyle partly across 
the tooth; the last lower molar is decidedly longer than mo and the 
crown pattern is more complicated than the corresponding tooth in 
Citellus; this tooth has an enlarged heel, with a greater develoj)ment 
of the enamel folds, which extend from the inner side and practically 
fill the talonid basin (pi. 12; pi. 14, G; pi. 17, G; pi. 20, A). 

The baculum of Cynomys ludovicianus resembles that of the 
ground squirrels in shape; it is 4.9 mm in length, the shaft rather 
stout and greatly thickened at the proximal end; the distal end is 
expanded in the shape of a deep scoop, the edges of which are irreg- 
ularly denticulate; the shaft is continued on the under side of the 
scoop as a narrow process (pi. 13, M) . 

Subgenus CYNOMYS 

Characters as given above for the genus ; further characterized by 
the relatively heavy jugal, which at the angle of the ascending branch 
is thickened and shows a prominent triangular process. 

Subgenus LEUCOCROSSUROMYS 

Leucocrossuromys Hoixistee, North Amer. Fauna 40: 23, 1916 (type, Spermo- 
philus gunnisoni Baird). 



1938] REVISION OF THE GROUND SQUIRRELS 39 

The skull of this subgenus is similar to that of typical Cynomys; 
the general shape of the occipital region, viewed from behind, is 
elliptical-oval; the jugal is relatively "weak, thin, and flat, the outer 
surface at angle of ascending branch only very slightly thickened, 
the margin rounded, not triangular" (HoUister, op. cit.). 

Genus CITELLUS: Ground Squirrels 

Citellus Oken, Lehrbuch der Zoologie (3) 2: S42, 1816 (type, Mus citellus Lin- 
naeus). 

The ground squirrels are represented in North America by 31 
species arranged in 8 subgenera and 12 well-marked groups, easily 
distinguished by their color pattern. These comprise the species 
commonly referred to typical Citellus (in which are represented sev- 
eral minor groups) ; the striped and the spotted ground squirrels 
{Ictidomys) ; Franklin's ground squirrel {PoliociteUus) ; rock squir- 
rels {Otospermophilus) \ ring-tailed ground squirrels {N otocitellus) 
antelope squirrels {Ammospermophilus) ; desert ground squirrels 
(Xerospermophilus) , containing only two plain-colored forms; and 
mantled ground squirrels {Callospermophilus). 

Some of these groups now rank as genera, others as subgenera; 
Ammospermophilus and Callospermophilus apparently have been 
accorded generic rank largely by reason of their external characters. 
Detailed comparison of the skulls of all the species of ground squir- 
rels shows them to be closely related, the various groups differing in 
relative proportions of the skull and teeth. 

The molars vary in height of crown from the hypsodont type found 
in typical Citellus to the brachydont type found m Otospermophilus^ 
Callospermophilus^ and Ammospermophilus ; the anterior premolar 
(always present) varies from the large functional tooth found in G. 
parryii — fully one-third as large as the adjoining premolar (pm*) — 
to the small, peglike tooth of Ammospermophilus, which is scarcely 
one-tenth as large as the next premolar, and but little larger than the 
corresponding tooth in Eutamias. 

The upper incisors vary from a long, slender, forward-projecting 
type found in C. parryii to the short, stout, recurved teeth of C. 
armulatus, which in this character strongly resembles some of the 
tree squirrels. 

GENERIC CHARAOTEBS 

The genus Citellus differs from Sciurus in having a much shal- 
lower brain case; the zygomata are contracted anteriorly, the an- 
terior portion twisted toward a horizontal plane; the upper surface 
of the jugal is without a prominent process; the antorbital foramen 
forms a canal, oval or subtriangular in shape ; the molarif orm teeth 
are less primitive and usually much more hypsodont; pm^ is always 
present, though variable in size. Citellus differs from Cynomys as 
follows : Upper molariform tooth rows parallel or only slightly con- 
vergent posteriorly ; upper molars relatively lighter and less hypso- 
dont; last upper molar with enamel pattern less complicated, the 
metaloph present in some species, absent in others, but never with an 
additional subsidiary loph; last lower molar likewise with less com- 
plicated enamel folding, the talonid basin present, as in m^ and m^. 



40 NORTH AMERICAN FAUNA INo. 56 

Subgenus CITELLUS 

Type. — Mus citellus Linnaeus. 

CKANIAI, CHABACTEBS 

Dorsal profile of skull moderately convex; parietal ridges faintly 
indicated ; brain case subglobular, about as broad as long ; postorbital 
processes long, slender, and decurved; zygomata moderately heavy, 
broadly expanded posteriorly, narrowing strongly anteriorly; antor- 
bital foramen large, suborbicular. 

Molarif orm tooth rows parallel or slightly convergent posteriorly ; 
upper incisors relatively slender; anterior upper premolar (pm^) 
more than one-third the size of pm^, bearing a simple, functional, 
obliquely transverse ridge; molars hypsodont, broader than long; 
transverse ridges on pm*, m^, and m^ forming a narrow U ; parastyle 
ridge on ni^ and m^ very low, joining protocone with an abrupt 
change of direction (almost a ri^ht angle) ; m^ with posterior loph 
obsolete in some species, present m others, and variable in some, 

A series of 12 specimens of O. citellus — ^type of the genus — from 
Hungary, recently acquired through the cooperation of the Hun- 
garian National Museum, makes it possible to define the characters 
of the type species in comparison with the American species of the 
genus. The skull of C. citellus (pi. 14, E; pi. 17, E; pi. 20, D) is 
similar in general to that of O. heldingi, but slightly smaller and 
more weakly built ; dorsal profile moderately convex ; parietal ridges 
slightly indicated; brain case subglobular, about as broad as long; 
posterior truncation of brain case nearly vertical; lambdoid crest 
moderately prominent; paroccipital processes moderate; interorbital 
breadth somewhat less than postorbital constriction ; postorbital pro- 
cesses long, slender, and decurved; zygomata moderately heavy, 
broadly expanded posteriorly, narrowing strongly anteriorly; ros- 
trum narrow, its sides nearly parallel ; nasals narrowing slightly pos- 
teriorly, extending slightly beyond nasal branches of premaxillaries ; 
antorbital foramen large, suborbicular; incisive foramina short and 
broad ; molarif orm tooth rows slightly convergent posteriorly ; ptery- 
goids long and slender; auditory bullae moderately inflated and 
evenly rounded, without external meatus. 

Upper incisors slender, nearly perpendicular to basi-cranial axis; 
molars hypsodont, broader than long ; anterior upper premolar (pm^) . 
more than one-third the size of pm^, bearing a simple, functional, 
obliquely transverse ridge; pm*, m^, and m^ with high transverse 
ridges forming a narrow U ; parastyle ridge on m^ and m^ very low, 
joining protocone at almost a right angle ; metastyle on pm*, m}, and 
m^ low and weakly developed, not directly joined to the protocone; 
m^ with posterior ridge (metaloph) obsolete; lower molars hypso- 
dont, the anterior cusps much higher than the posterior, with a dis- 
tinct narrow transverse ridge joining the protoconid with the par- 
aconid ; prrii with the two anterior cusps separated by a broad sulcus. 

External chabacteiss 

The species associated in the typical subgenus Citellus vary greatly 
in external characters. In all forms the ears are rather low, in some 
but little raised above the crown, in others of medium height, but 



1938] REVISION OF THE GROUND SQUIRRELS 41 

not pointed. The tail may be about half the length of the body or 
much shorter. The coloration varies from plain to mottled or 
spotted. 

BACULAB CHAEACTEES 

The baculum from a specimen of Citellus heldingi oregonus is 3.5 
mm in length; its shaft is broad at the base, slightly curved, and 
narrowed toward the tip, which is shaped like a spoon with a crenu- 
late border. The apex of the shaft appears as a short process pro- 
jecting from the lower surface of the terminal disk (pi. 13, Q). 

Subgenus ICTIDOMYS 

Ictidomys Allen, Moiiog. North Ainer. Rodentia, p. 821, 1877 (type, Sciurus 

tridecemlineatus Mitchill). 
Ictidomoides Mearns, U. S. Natl. Mus. Bull. 56: 328, 1907 (type, Sciurus mexi- 

canus Erxleben). 

As originally proposed by Allen the subgenus Ictidomys com- 
prised the species tereticaudus, mexicanus^ trideceinlineatus, and 
franklinii. The type has been fixed by Merriam (Allen, 1895a, p. 
418) as Citellus tridecemlineatus] tereticaudus has been removed to 
another subgenus and franklinii is here made the type of a new 
subgenus. Ictidomoides^ proposed by Mearns (1907, p. 328) for C. 
mexicanus, appears to be inseparable from Ictidomys. C. spilosoma 
and 0. perotensis are also included in this subgenus. 

CBANIAL CHAKACTB3ES 

Ictidomys differs from typical Citellus in having a relatively nar- 
rower brain case; the rostrum tapering gradually; upper incisors 
relatively stouter, shorter, and distinctly recurved; anterior upper 
premolar relatively much smaller (less than one-third as large as 
pm*)^ its crown sometimes developing a short cutting edge, but often 
appearing as a single cusp; metaloph of pm*'^ m^, and m^ not con- 
tinuous, the metacone separated from the protocone by a distinct 
sulcus; on m^ the metaloph is obsolete (pi. 14, C ; pi. 17, G ; pi. 20, H). 

E3TEENAI, CHARACTERS 

Body rather slender; tail distichous, 60 to 80 percent of the head 
and body; ears short and broad, rising but little above the crown; 
claws on front feet long and slender, the third longest, the second 
and fourth about equal, the fifth much shorter; thumb very short, 
but bearing a rudimentary claw. Claws on hind feet shorter and 
stouter, the first very short, the fifth somewhat longer, second and 
fourth about equal, and third slightly longer. Cheek pouches of 
moderate size; mammae usually 10 or 12: pectoral, f, abdominal, 
f or f , inguinal, \. 

The pelage in this subgenus is dense and soft, and of moderate 
length. Apparently there is but one molt annually, occurring in 
April or May, but its progress is not clearly shown by any of the 
specimens examined. 

The color pattern in the type species consists of a series of alter- 
nating light and dark stripes, with whitish spots in the middle of 



42 NORTH AMERICAN FAUNA [No. 56 

the dark stripes; in G. mexicanus the dorsal stripes are all broken 
into spots; G. spilosoma and G. perotensis are irregularly spotted on 
a plain background. 

BACTDIAE CHABACTEES 

The baculum of G. tridecemlineatus — ^the type of this subgenus — 
consists of a nearly straight shaft 4.9 mm long, much thickened at 
the proximal end, tapering rather abruptly, the distal end upturned 
and widely expanded into a shallow "scoop", with a wide cleft in the 
center ; the margin of the scoop on either side with shallow crenula- 
tions ; there is no process at the tip of the shaft (pi. 13, N) . 

The baculum of G. mexicanus is similar to that of G. tridecem- 
Uneatm, but the tip is less widely expanded and more sharply up- 
turned on the sides, thus producing a deeper hollow in the center of 
the scoop. The tip of the shaft shows as a process from the under 
side of the scoop. As in G. tridecemlineatits, the border of the disk 
shows slight crenulations (pi. 13, 0). 

POLIOCITELLUS, enbgenns nov. 

Type. — Arctomys franklinii Sabine. 

CBANIAX CHARACTERS 

Gitellus franklinii differs in many rather striking characters from 
the other ground squirrels and may well be recognized as a sub- 
genus. In many of its characters it furnishes a connecting link 
between Ictidomys and Otospermophilus. It differs from Gitellus 
in the general contour of the skull, which is relatively long and nar- 
row, with the superior outline flattened and the rostrum not pinched 
in at base. The zygomata are less widely expanded than in Gitellus 
cr Otosjyertnophilus ; the interorbital region is much longer than hi 
Gitellus^ much as in Otospermophilus but relatively narrower; its 
border is usually without a notch, the supraorbital foramen closed 
in the majority of specimens; the postorbital processes are much as 
in Gitellus — slenderer than in Otospermophilus — ^the upper incisors 
resemble those of Otospermophilus^ and are stouter than those of 
Gitellus; the upper molars are similar to those of Otospermophilus^ 
but somewhat more hypsodont, the accessory tubercles on rn} and m^ 
more prominent. Compared with Gitellus the upper molars are much 
lower-crowned and relatively longer (antero-posteriorly) ; the para- 
style ridge rises gradually to join the protocone, without an abrupt 
change in direction; the transverse ridges are more widely spaced 
and the metaloph on pm^^ m^, and m^ is frequently discontinuous; on 
m^ the metaloph is absent. The anterior upper premolar {pm^) is 
peculiar, usually showing two distinct cusps, the outer one being 
higher than the inner. This tooth is relatively larger than in Oto- 
speTTYhophilus but not as large as in Gitellus^ being one-fourth to one- 
third the size of pm" (pi. 14, B; pi. 17, B; pi. 20, E). 

EXTEENAL CHABACTEES 

Body and limbs slender, resembling those of the tree squirrels 
{Sciurus) ; tail more than half as long as the head and body, some- 



1938] REVISION OF THE GROUND SQUIRRELS 43 

what bushy ; ears low and evenly rounded ; coloration uniform, with 
indistinct mottling; mammae 10 or 12; pectoral, f ; abdominal, j- or f; 
inguinal, f ; cheek pouches small; claws stout, slightly curved. 

The pelage is dense and rather harsh; plain or dappled; the 
method and time of molting is not evident from examination of 
museum specimens. 

BACULAB CHABACTEES 

Baculum 4.3 mm in length, shorter and stouter than that of G. tri- 
decemlineatus^ the shaft sharply bent upward near the terminal disk, 
which is 1.6 mm broad, shaped like a saucer and without pronounced 
crenulations on its margin. The tip of the shaft projects from the 
under side of the disk as a flattened process having a shallow sulcus 
on the anterior border (pi. 13, P). 

Subgenus OTOSPERMOPHILUS 

OtospermopMlus Brandt, Bull. Class. Phys.-Math. Acad. Imp. Sci. St. Peters- 
bourg, 2: 379, 1844 (type, Sciurus grammurus Say). 

The subgenus Otospermophilus^ proposed for the "eared spermo- 
philes", comprising the rock squirrels {heecheyi, grammurus^ etc.), 
G. {C ollosperTno'philus) lateralis, and G. (Ictidomys) mexicanus^ 
has been restricted by elimination to the Gitellus heecheyi-graniTnu- 
rus group. 

CRANIAL CHAKACTEBS 

Skull similar to that of Gitellus {Poliocitellus) franklinii, but 
brain case broader and relatively shallower; interorbital region 
broader; rostrum short and broad, tapering gradually; antorbital 
foramen narrowly oval. Upper incisors stout, recurved; anterior 
upper premolar relatively small, about one-sixth the size of pm*; 
upper molars low-crowned, nearly quadrate; transverse ridges on 
pm*, m^, and m^ more widely separated than in typical Gitellus and 
less completely united with the protocone ; posterior loph on m} and 
m^ frequently broken up into one or two islandlike cusps; m^ with- 
out metaloph (pi. 15, /^; pi. 18, F\ pi. 21, G). 

EXTEBNAL CHABACTEBS 

Body and limbs moderately slender; ears larger than in Polio- 
citellus or typical Gitellus; tail about two-thirds the length of the 
head and body, somewhat bushy; cheek pouches large. 

BACTJLAB CH^VEACTERS 

The baculum of a specimen of 0. variegatus grammurus (pi. 13, 
G) from Tucson, Ariz., is similar to that of G. {Gitellus) heldingi 
oregonus but is slightly longer (4.5 mm) with fewer "teeth" on 
the terminal portion ; the shaft is nearly straight, and its tip projects 
beyond the triangular-shaped "spoon" as a prominent j)rocess. 
Another specimen (pi. 13, H) differs from the one just described in 
being more strongly curved, and instead of a spoon-shaped disk at 
the tip the baculum divides into three blunt processes. This sug- 
gests that in a larger series other variations may occur. A baculum 
of G. V. huchleyi (pi. 13, /) resembles that of G. v. grammurus, but 
the disk is narrower. 



44 NORTH AMERICAN FAUNA [No. 56 

NOTOCITELLUS, subgenus nov. 

Type. — Spermophilus annulatus Audubon and Bachman. 

CEANIAI, CHABACTEES 

Skull similar to that of Citellus {Otospermo'philus) heecheyi but 
interorbital region relatively broader; supraorbital foramen always 
closed; rostrum short, the nasals relatively broader posteriorly; 
zygomata less widely expanded posteriorly; incisors relatively 
shorter and thicker antero-posteriorly ; molariform teeth as in Oto- 
spermophilus. Compared with G. {Poliocitellus) franklinii the 
skull of Notocitellus is relatively broader in the interorbital region, 
the rostrum is shorter and broader, and the molariform teeth are 
lower crowned, with p^ relatively smaller (pi. 26, D\ pi. 31, D). 

EXTEENAL CHAEACTEBS 

Form slender; tail more than two-thirds the length of head and 
body, distichous, not bushy ; feet long and slender ; claws sharp, re- 
curved ; ears shorter and less pointed than in Otospermophilus^ their 
superior margin evenly rounded. Pelage thin and somewhat harsh. 
Color pattern plain. Cheek pouches large {fide Audubon and Bach- 
man). 

Subgenus AMMOSPERMOPHILUS 

AmmospermopMlus Merriam, Biol. Soc. Wash. Proc. 7 : 27, April 13, 1892 
(type, Tamias leucurus Merriam). 

CEANIAL CHAEACTEES 

Skull similar to that of Otospermophilus, but brain case more rec- 
tangular, relatively broader at the posterior end, and distinctly 
flattened on the upper surface; lambdoid crest much reduced; audi- 
tal bullae relatively larger; zygomata appressed, only slightly ex- 
panded at posterior end. 

This subgenus agrees with Otospermophilus in the shape of the 
antorbital foramen and in the attachment of the maxillary roots 
of the zygomata. The postorbital processes are small and slender; 
the upper incisors are stout and recurved much as in O. adocetus; 
the molariform teeth are essentially like those of Otospermophilus; 
the anterior upper premolar is a small, simple, peglike tooth, but 
little larger than the corresponding tooth in Eutamias (pi. 15, E ; 
pi. 18, ^/pl. 21, Z>). 

EXTEENAL CHAEACTEES 

Form as in most of the small ground squirrels; legs rather short, 
tail about half the length of the body, distichous, well-haired; ears 
short, broad and rounded; cheek pouches large; mammae, 10. The 
color pattern consists of a uniform background, with a single lon- 
gitudinal white stripe on each side. 

ilBACULAE CHAEACTEBS 

The baculum resembles that of the subgenus Citellus; the prox- 
imal end of the bone is thickened and laterally expanded ; the shaft 
is straight and slender ; ih& distal end is bent at right angles to the 



1938] REVISION OF THE GROUND SQUIRRELS 45 

shaft, and expanded into the shape of a shallow scoop, the edges of 
which are crenulate. Two specimens measured, respectively, 1.5 
nmi and 2.2 mm in length (pi. 13, K and Z). 

Subgenus XEROSPERMOPHILUS 

Xerospermophilus Merriam, Biol. Soc. Wash. Proc. 7:27, April 13, 1892 (type, 
Spermophilus mohavensis Merriam). 

CEANIAL CHARACTERS 

Skull short and broad, similar in general shape to that of Citellus 
townsendii inollis but relatively broader in the interorbital region; 
postorbital processes shorter, broad at base, rapidly tapering to a 
point ; rostrum short and broad, tapering gradually ; brain case broad 
and slightly flattened; zygomata stout and moderately expanded; 
upper incisors moderately stout and slightly recurved ; molars brachy- 
dont (much as in Otospermophilus) ; ni^ and ni- slightly broader than 
long, the transverse ridges rather widely spaced ; anterior upper pre- 
molar small, less than one-fourth the size of ■pm'^\ audital bullae 
moderately inflated. 

Compared with AmmospermopJdlus this subgenus differs in hav- 
ing a shorter brain case ; heavier zygomata ; interorbital region nar- 
rower; antorbital foramen broader and more orbicular; anterior up- 
per premolar relatively larger ; postorbital processes stouter ; audital 
bullae smaller (pi. 14, Z>; pi. 17, D; pi. 20, 5). 

EXTERNAL CHARACTEJES 

Body stocky; feet stout; claws long, sharp, curved; soles densely 
haired; palms naked; thumb rudimentary^ bearing a broad nail; 
teats, 10; ears very low — a mere rim — tail 40-60 percent of the 
body length, somewhat cylindrical, well haired, but appearing terete 
when worn; pelage soft and silky when fresh, harsh when worn; 
coloration plain. 

BACULAE CHARACTERS 

The baculum of Citellus tereticaudus is similar to that of C. 
grammurus, but shorter, measuring 3.5 rnm in length; the shaft is 
much enlarged at the base and slightly curved upward; the tip 
broadens out to form a nearly circular "spoon" with pronounced 
crenulations on the margin; the tip of the shaft projects well be- 
yond the border of the disk on the under side (pi. 13, R). 

Subgenus CALLOSPEKMOPHILUS 

Callospermophtlus Merriam, Biol. Soc. Wash. Proc. 11: 189, July 1, 1897 (type, 
ScAurus lateralis Say). 

CRANIAL CHARACTERS 

Skull very similar in general shape and in proportions to that of 
Otospermophilus^ but upper incisors relatively slenderer and less 
chiseled off on inner face ; molarif orm teeth not appreciably different. 
Compared with Notocitellus : Skull relatively narrower interorbitally, 
the supraorbital foramen opening into the orbit; rostrum relatively 
narrower; upper incisors decidedly slenderer, zygomata more widely 



46 NORTH AMERICAN FAUNA [No. 56 

spread posteriorly; incisive foramina relatively larger (pi. 14, A] 
pi. 17, A; pi. 20, G). 

EXTEENAL CHARACTERS 

Body rather stout ; legs short ; tail usually more than half as long 
as the head and body (about one-third as long in Gitelhis madren- 
sis), distichous, well haired, ears large, rounded on superior margin 
(height from notch, 13 to 18.5 mm) ; claws slender, sharp, recurved; 
thumb rudimentary, bearing a short, broad nail ; cheek pouches large ; 
mammae 8 or 10. The color pattern consists of a longitudinal white 
stripe on each side of the back, bordered on one or both sides with a 
black stripe. 

BAOtTLAE CHABACTERS 

The baculum is a tiny bone, 2 mm in length, irregularly spatulate 
in shape. It has been dissected out in only one instance, and may not 
always be present (pi. 13,/). 

CHIPMUNKS 

The chipmunks (genera Tamias and Eutamias) are more nearly 
related to the ground squirrels than to the tree squirrels. The essen- 
tial characters distinguishing these two genera from Citellus (includ- 
ing all the subgenera) are as follows: Absence of an antorbital 
canal, the antorbital foramen being a relatively large opening in the 
zygomatic process of the maxillary ; the anterior border of the zygo- 
matic notch in the maxillary is opposite pmJ^ instead of m} as in all 
the ground squirrels; the transverse ridges on m} and mr are not 
parallel, the posterior loph being slightly divergent externally. 

Genus TAMIAS: Eastern Chipmunks 

Tamias Illiger, Prodromus Systematis Mammalium et Avium, p. 83, 1811 (type, 
Sciurus striatus Linnaeus). 

In general contour the skull of Tamias most nearly resembles that 
of Citellus {Notocifellus) annulatus. It differs from it and from all 
the ground squirrels in the absence of pm^ ; in the shape and position 
of the antorbital foramen; and in the attachment of the anterior 
root of the zygomata. The posterior border of the zygomatic plate 
of the maxillary is opposite the extreme posterior part of pm^ or 
sometimes the anterior edge of m?-. 

The superior outline of the skull is flat, and the brain case is shal- 
low; the upper incisors are short, moderately stout, and slightly 
recurved. The molars are low crowned, the cusps wide spaced, with 
slightly developed subsidiary cusplets between the primary cusps 
(pi. 15, 5; pi. 18, B; pi. 21, E). 

The color pattern consists of five blackish and two whitish longi- 
tudinal stripes on the dorsal area ; a median black stripe is bordered 
on each side with a broad band of gray or tawny about twice the 
width of the median stripe ; on either side of these dorsal bands are 
a pair of shorter blackish stripes with a whitish stripe between them. 

The baculumj of Tamias striatus is about 4.5 mm m length, nearly 
straight, but upturned at the tip and slightly expanded into the shape 
of a narrow spoon or scoop, with a slight median ridge on the under 
surface (pi. 13, A and B). 



1938] REVISION OF THE GROUND SQUIRRELS 47 

Genus EUTAMIAS: Western Chipmunks 

Eutamias Trouessart, Bull. Soc. d'Etudes Sci. d' Angers 10 (1) : 86, 1880 (type, 
Sciurus striatus asiaticus Gmelin). 

The western chipmunks are closely related to the eastern chip- 
munks {Tamias). The genus occurs also in eastern Asia, and the 
American species show some distinctive group characters, considered 
of subgeneric value. 

Compared with Tamias^ the skull of Eutamias has the rostrum 
shorter and more abruptly constricted at the base; the brain case is 
smoothly rounded, slightly flattened or moderately inflated ; the pal- 
ate is relatively shorter, terminating on the plane of last molars or 
but little posterior to it ; the notch in the zygomatic plate of the max- 
illary projects slightly more forward, usually being opposite the 
middle or posterior part of /?m'^; the audital bullae are relatively 
large; the upper incisors show numerous longitudinal striations, 
' which in some species are well-defined grooves ; the molarif orm teeth 
are much as in Tamias^ but the anterior premolar {jpm^') is always 
present as a small peglike tooth. The color pattern is distinctive, 
consisting of five blackish and four whitish longitudinal stripes, all 
of approximately equal width (pi. 15, C\ pi. 18, G\ pi. 21, H). 

Subgenus EUTAMIAS 

The type of Eutamias is E. asiaticus of eastern Asia. The cranial 
characters distinguishing this subgenus from the American sub- 
genus Neotamias are as follows: Interorbital constriction slight (as 
in Tamias) ; postorbital processes broad at base, tapering to a point 
(much as in Tamias) ; antorbital foramen large, suborbicular (as in 
Tamias) ; lambdoidal crest moderately developed; upper molariform 
tooth rows slightly convergent posteriorly (as in Tamias) ; palate 
short, ending about on plane of last molars. In several of its char- 
acters this subgenus resembles Tamias more than it does the Ameri- 
can Neotamias. 

The baculum of E. asiaticus (one specimen) differs from that of 
the American species of Neotamias in being much more slender. It 
is 5 mm in length and tapers gradually from base to tip; the distal 
portion is upturned in an even curve and slightly flattened, but with- 
out ridges (pi. 13, C). 

Sabgenns NEOTAMIAS 

Neotamias Howell, North Amer. Fauna 52: 26, 1929 (type, Tamias asiaticus 
merriami Allen). 

The American members of the genus Eutamias present a number 
of characters distinguishing them from the typical members of the 
genus, which are confined to Asia. The postorbital processes are nar- 
rower at the base and much slenderer throughout; the interorbital 
constriction is more pronounced; the lambdoidal crest less strongly 
developed; the antorbital foramen smaller and narrowly oval rather 
than orbicular ; the palate ends slightly posterior to the plane of the 
last molars; the upper tooth rows are more nearly parallel. The 
ears are relatively longer and more pointed. 

The baculum in the members of this subgenus differs from that 
of both Tamias and typical Eutamias; specimens examined of six 



4g NORTH AMERICAN FAUNA [No. 56 

species show essential similarity in form but some variation in size. 
In a specimen of E. quadrivittatus f rater (pi. 13, E)^ the baculum 
resembles a human leg in general shape; it is 3.8 mm in length, 
thickest at the proximal end, and tapers gradually to the tip with 
a sharp bend in the middle of the shaft; the distal end is bent 
upward at almost a right angle, expanded and flattened in the shape 
of a human foot, with a prominent narrow ridge in the center of 
the "instep." In a specimen of E. cinereicoUis (pi. 13, F) the bac- 
ulum is 4.7 mm long and the shaft is stouter throughout. Bacula 
of E. toiunsendii sonomae (pi. 13, D) and E. dorsalis are about 4.5 
mm in length and slenderer than in the other species examined. 

Genus SCIURUS: Tree Squirrels 

Sciurus Linnaeus, Systema Naturae (10) 1: 63, 1758 (type, Sclurus vulgaris 
Linnaeus). 

The North American tree squirrels are all remarkably alike in 
cranial characters, and not widely different from the typical spe- 
cies — /Sciurus vulgaris of Europe. South America has produced a 
number of aberrant groups that have been given the rank of genera 
(Allen, 1915, p. 147). These have not been studied by the writer. 

As already pointed out, the tree squirrels are distinguished from 
the ground squirrels and chipmunks by the great breadth of the 
interorbital region and the great depth of the brain case; the zygo- 
mata are nearly parallel to the axis of the skull and nearly vertical 
(not twisted as in Citellus), with an angular process on the upper 
surface of the jugal; the antorbital canal is a narrow vertical slit; 
the upper incisors are compressed laterallj^ and are relatively deep 
(much like those of Otospermophilus) . The molars are always low 
crowned and simple. The anterior upper premolar (pm^) is absent 
in some groups, present in others, but always very small. 

Subgenus SCIURUS 

The typical subgenus is not represented in America. 

The skull of the type species — Sciurus vulgaris of Europe — ^is 
relatively short and broad; the brain case strongly deflected at pos- 
terior end; a shallow depression in the anterior frontals with a 
swelling on posterior frontals ; zygomata nearly parallel, moderately 
expanded ; postorbital processes broad at base, tapering abruptly to a 
Ipng, slender point, depressed and directed backwards; antorbital 
foramen triangular, broadest at base; notch in maxillary plate of 
zygoma opposite pm^; prn? present, but very small and not rising 
to the level of pm^ ; pmJ^ subquadrate, narrowest on the inner side 
(pi. 16, F; pi. 19, F; pi. 22, D). 

The baculum of S. vulgaris^ according to Thomas (1915, p. 384), 
is essentially like that of S. carolinensis. 

Subgenus NEOSCIURUS 

Neosciurus Trouessart, Le Naturaliste 2 (37): 292, October 1880; Catalogus 
Mammalium, Rodentia, p. 76, 1880 (part) (type, Sciurus carolinensis 
Gmelin) . 

EcMnosciurus Trouessart, Idem (type, Sciurus hypopyrrhus Wagler = S. aure- 
ogaster hypopyrrhus). 



1938] REVISION OF THE GROUND SQUIRRELS 49 

Baiosciurus Nelson, Wash. Acad. Sci. Proc. 1: 31, May 9, 1899 (type, Scmrus 
deppei Peters). 

The skull of Sciurus caroUnensis — the type of the subgenus Neo- 
sciurus — does not differ widely in general shape from that of S. 
vulgaris but is relatively longer, with the brain case shallower and 
more elongated (less globular) and the rostrum longer and rela- 
tively narrower; the postorbital processes are shorter and stouter; 
the notch in the zygomatic plate of the maxillary is opposite m^ 
(instead of pm*) ; pm^ is present but not strongly developed; pm* 
is triangular rather than quadrate in outline, owing to the greater 
production of the parastyle QdI. 15, E; pi. 18, H; pi. 21, F) . 

In S. deppei (type of Baiosciurus Nelson), prn^ averages slightly 
more quadrate than the same tooth in Neosciurus^ but examination 
of a large series of deppei and cai'olinensis shows that the character 
is too slight and inconstant to serve as a basis for subgeneric 
distinction. 

Sciurus aii/reogaster hypopyrrhus and the large group of Mexican 
forms associated with it by Nelson in the subgenus Echino sciurus 
differ in general from 8. carolinensis in having a shorter and rela- 
tively broader rostrum and a more or less prominent depression in 
the frontals; these differences, however, are considered too slight 
to warrant recognition of the group. 

The baculum of Sciurus carolinensis is apparently closely similar 
to that of Sciurus vidgaris. It is 10.5 mm in length, the shaft stout, 
but tapering distally, curved upward near the tip, and flattened into 
the shape of a shallow scoop with the edges rolled up; on the lower 
side of the scoop is a small, blunt process (pi. 13, S). The baculum 
of S. deppei and that of S. adolphei dorsalis (pi. 13, T) agree essen- 
tially with that of S. carolinensis. 

The following species are included in Neosciurus: S. carolinensis, 
S. deppei, S. aureogasier, S. poliopus, S. yucatanensis, S. colliaei, 
S. truei, S. sinaloensis, S. nelsoni, S. socialis, S. griseo/lavus, S. 
goldmani, S. managuensis, S. boothiae, S. adolphei, S. thomasi, and 
S. variegatoides. 

Subgenus HESPEROSCIURUS 

Hesperosciurus Nelson, Wash. Acad. Sci. Proc. 1: 27, May 9, 1899 (type, 
Sciurus griseus Ord). 

The skull of Sciurus griseus resembles that of S. carolinensis very 
closely, except that it is larger ; pm* averages slightly more quadrate 
(less triangular), but examination of a large series of both species 
shows the character to be inconstant. The jugal is relatively lighter 
(shallower) and viewed from beneath shows less twisting from the 
vertical plane (pi. 15, G; pi. 18, G; pi. 21, A). 

The baculum is widely different from that of Neosciurus, re- 
sembling more closely that of S. aberti. The bone measuring 16.5 
mm in length, is moderately curved and ends in a blade about 6.8 
mm in length, with a curved and slightly twisted edge; the tip of 
the blade is a blunt point, but at its posterior end it forms a short, 
sharp hook (pi. 13, V). 

This subgenus comprises but one species S. griseics, of the Pacific 
coast region of the United States. 

154970—38 4 



50 NORTH AMERICAN FAUNA [No. 56 

Subgenus OTOSCIURUS 

Otosciurus Nelson, Wash. Acad. Sci. Proc. 1: 28, May 9, 1899 (type, Sciurus 
aberti Woodhouse). 

In general shape the skull of Sciurus aberti closely resembles that 
of S. vulgaris; pm^ is relatively larger and more strongly developed, 
the crown being subject to wear with the rest of the molar series; 
the notch in the zygomatic plate of the maxillary is opposite the 
middle portion of m}. 

Compared with Neosciurus, this subgenus differs in having the 
brain case and interorbital region relatively broader; postorbital 
breadth less than the interorbital breadth; postorbital processes 
larger and longer; postorbital notch deeper; pm? more strongly de- 
veloped (pi. 16, E; pi. 19, E; pi. 22, ^) . 

The baculum is widely different from that of typical Sciurus and 
of S. carolinensis, and bears closer resemblance to that of S. griseus. 
It is a nearly straight bone, 16.1 nun in length, the distal portion flat- 
tened laterally into the shape of a blade with a curved edge ; on the 
lower side of the blade is a small tubercle (pi. 13, W). 

The species included in Otosciurus are: S. aberti^ S. kaihahensis, 
S. concolor, and S. durangi. 

Subgenus PARASCIURUS 

Parasciurus Trouessart, Le Naturaliste 2 (37) : 292, October 1880 (type, 

Sciurus niger Linnaeus). 
Araeosciurus Nelson, Wash. Acad. Sci. Proc. 1 : 29, May 9, 1899. 

The fox squirrels differ from the other North American squirrels 
(except Guerlinguetus) in the entire absence of pm?. Compared 
with Neosciurus the skull is of very similar shape, the brain case 
somewhat shallower and more flattened; the frontals are slightly 
elevated on the posterior half ; there is a distinct interorbital notch ; 
the notch in the maxillary plate is opposite the middle or hinder part 
of m^; the molariform teeth are very similar to those of Neosciurus 
(pi. 16, (7/ pi. 19, ^/ pi. 22, .g). 

The baculum is likewise closely similar in shape to that of 
Sciurus carolinensis (pi. 13, U). 

The subgenus comprises the following species: S. niger, S. ari- 
sonensis, S. apache, S. alleni, S. nayaritensis, and S. oculatus. 

Subgenus GUERLINGUETUS 

Ouerlinguetus Gray, London Med. Repos. 15: 304, 1821 (type, Sciurus guer- 

Unguetus Gray = S. aestuans Linnaeus). 
Mesosciurus Allen, Amer. Mus. Nat. Hist. Bull. 34 : 212, 1915.* 

The skull of Sciurus aestuans ^ is similar in shape and size to that 
of Tamiasciurus hudsonicus but has a deeper and more highly arched 
cranium; the rostrum is short and strongly "pinched in"; the 
zygomata are nearly parallel to the axis of the skull ; the postorbital 
processes are short and slender; the hinder portion of the frontals 
is swollen; the notch in the maxillary plate is opposite the hinder 
part of pm^ or the division between this tooth and m^; there is but 

* Allen proposed Mesosciurus as a genus mainly on the possession of eight mammae 
instead of six, as in Ouerlinguetus ; he states that there is "no very marked difference" in 
cranial or dental characters between these two groups. 

^ Comparisons were made with a series of skulls from British Guiana, borrowed from 
the American Museum of Natural History (nos. 34874, 42344, 48137, 48392). 



1938] REVISION OF THE GROUND SQUIRRELS 51 

one upper premolar (pm^), which is subcircular or quadrate in 
shape, differing thus from Parasciurus and Tamiasciuncs, in which 
this tooth is subtriangular. The skull differs from that of Parasciu- 
rus also in having a shorter rostrum, more swollen brain case, and m 
the position of the notch in the maxillary plate of the zygoma (pi, 
16, 5/ ph 19, 5/ pi. 22, F.) 

The subgenus GuerUnguetus is represented in North America by 
Sciurus richmondi^ S. hoffmanni^ and ^S". gerrardi. 

Genus TAMIASCIURUS : Red Squirrels 

Tatniasciurus Trouessart, Le Naturaliste 2 (37) : 292, October 1880 (type, 
Sciurus hiidsonicus Ersleben.) 

The red squirrels, or chickarees, differ from typical Sciurus in the 
vestigial character of the anterior upper premolar, which is often 
absent and when present is minute and never functional, being cov- 
ered by the crown of pm'^. The superior outline of the skull is much 
flatter, the brain case shallower and not strongly deflected posteri- 
orly; the zygomata are less expanded, being parallel to the axis of 
the skull ; the postorbital processes are much shorter. 

Compared with S. {Neosciunis) caroUnensis, T amiasciurns differs 
in the (usual) absence of pm^ and in having the notch in the zygo- 
matic plate of the maxillary opposite J9m* (instead of m})\ the 
rostrum is relatively shorter and broader, and tlie zygomata less 
expanded (pi. 16, D; pi. 19, D; pi. 22, E). 

Although the red squirrels exhibit no very marked cranial differ- 
ences from the other tree squirrels, the reproductive tract of the 
males is strikingly different from that of their relatives in the 
genus Sciurus. They have no baculum, and the penis is long and 
slender, tapering to a point. The anatomy of T amiasciurus hud- 
sonicus, in comparison with that of certain other sciurids, has been 
reported on by Mossman et al. (Mossman, Lawlah, and Bradley, 1932, 
p. 119) and their findings are summarized as follows: 

This species differs much more fundamentally from the sciurid type, such as 
8. carolinensis, than any other studied. The striking differences in the male 
are: minute Cowper's glands opening into the urethra in the bulb, no penile 
duct, no bulbar gland, a true urethral diverticulum in the bulb, a long filiform 
penis, and no os penis. The seminal vesicles are excessively large. Anal glands 
are present. The female also differs from other female Sciuridae examined in 
having an unusually long, coiled vagina during oestrus. 

Genus MICROSCIURUS: Pygmy Squirrels 

Microsciurus Allen, Amer. Mus. Nat. Hist. Bull. 7: 332, Nov. 8, 1895 (type 
Sciurus alfari Allen). 

The genus Microsciurus comprises the smallest of the North Amer- 
ican squirrels. The skull is highly arched, with a pronoiniced swell- 
ing on the frontals at the plane of the postorbital processes; brain 
case is strongly deflected at posterior end; rostrum is short and 
broad ; upper incisors project forward to or beyond the plane of the 
tip of nasals; jugal is relatively wide, inferior margin abruptlv 
depressed anteriorly where it joins the maxilla; pm^ is well devel- 
oped (pi. 15, />; pi, 18, Z>; pi. 21, B). 

Included in this genus are the species M. alfari, M. hoqi/rfensis^ 
M. isf.hmius, and M. septentrionalis in Central America, and others 
in South America, 



52 NORTH AMERICAN FAUNA [No. 56 

Genus SYNTHEOSCIURUS : Pygmy Squirrels 

Byntheosciurus Bangs, Mus. Comp. Zool. Bull. 39: 25, April 1902 (type, Syn- 
theosciurus brochus Bangs). 

The skull of Syntheosciurus is similar to that of Microsdurus but 
Avith cranium more highly arched; frontals swollen; upper incisors 
projected forward, and having a broad, shallow groove; molariform 
teeth relatively large, pm^ present, reaching the crown of ^m*; au- 
dital bullae small ; postorbital processes slender. 

The fur is woolly ; ears short, broad, and densely haired ; whiskers 
rather short ; tail round and bushy. 

The genus is known only from the type species, occurring in 
Chiriqui, Panama (pi. 16, A ; pi. 19, A ; pi. 22, G) . 

Genus GLAUCOMYS: Flying Squirrels 

Glaticomys Thomas, Ann. and Mag. Nat. Hist. (8) 1: 5, January 1908 (type, 
Mus volans Linnaeus) . 

The genus Glaucomys, which comprises the American flying 
squirrels, differs widely in cranial characters from all the other groups 
of the Sciuridae. The skull resembles that of Sciurus in the great 
depth of the brain case and the shape of the zygomata, which are 
vertical (not twisted as in the ground squirrels) ; it differs from 
Sciurus in the extreme constriction of the interorbital and postorbital 
regions and the presence of a deep interorbital notch ; the postorbital 
processes are slender and project about in the middle of the temporal 
fossa; the incisors are rather slender, and not recurved as in most 
of the tree squirrels. 

The skull agrees with that of the chipmunks (Eutamias) in the po- 
sition of the notch in the maxillary plate of the zygoma, which is 
opposite ^7?i*, but differs from them and agrees with the ground 
squirrels m the possession of an antorbital canal. The cusps on the 
outer side of the upper tooth row are higher than in Sciurus or 
Eutamias and are without subsidiary cusplets; pni^ is present and 
is relatively larger than in Eutmnias; ptn^ is subquadrate, nearly as 
large as m^^ with the parastyle ridge rising to form a cusp; the 
lower molars resemble those of Eutamias in having small cusplets 
between the primary cusps (pi. 15, A ; pi. 18, A ; pi. 21, C) . 

The baculum of Glaucomys volans is 12.5 mm in length and rela- 
tively much slenderer than in Sciurus \ the shaft is twisted at the 
proximal end, and the distal end is bifid; the distal half is com- 
pressed on one side into a thin blade reaching to the tip (pi. 13, X). 



REVISION OF THE GENUS CITELLUS 

[For generic characters see p. 39] 

Citellus Oken, Lehrbuch der Zoologie (pt. 3) 2:842, 1816, (type, Mus citellus 
Linnaeus). 

Anisonyx Rafinesque, Amer. Monthly Mag. 2 (1) : 45, 1817 (type, Anisonyx 
irachiura Rafinesque (^Arctomys coliiniManus Ord)). 

Spermophilus F. Cuvier, Dents des Mamm., p. 255, 1825, (type, "Mus citillus 
Linn."). 

Spermophila Richardson, Parry's Second "Voyage, App., p. 313, 1825. 

Spermophillus Cuvier, Diet Sci. Nat. 59 : 473. 1829. 

Spermatophihis Wagler, Nat. Syst. Amphibien, p. 22, 1830. 

Spermophilis Richardson, Zool. Voyage H. M. S. "Blossom" ; Mamm., p. 12, 1839. 
■Citillus Lichtenstein, Darst. neuer oder wenig bekannt. Sauget., pi 31, fig. 2 
(not paged), 1830. 

Colohotis Brandt, Bull. Class. Phys.-Math. Acad. Imp. Sci. St. Petersbourg, 2 
(23 and 24) : 366, 1844 (type, Spennophilus fulvus Lichtenstein). 

Otocolotus Brandt, op. cit., p. 382 { = Colodotis). 

Otospermophilus Brandt, op. cit., p. 379 (type, Sciurus grammurus Say). 

Colobates Milne-Edwards, Recherches Hist. Nat. Mamm. 1 : 157, 1868-74. 

Ictidomys Allen, Monog. North Amer. Rodentia, p. 821, 1877 (type, Sciurus 
tridecenilineatus Mitchill) . 

XerospermopMlus Merriam, Biol. Soc. Wash. Proc. 7: 27, 1892 (type, Spermo- 
philus mohavensis Merriam). 

Ammospermophilus Merriam, Biol. Soc. Wash. Proc. 7: 27, 1892 (type, Spermo- 
philus leucurus Merriam). 

Callospermophilus Merriam, Biol. Soc. Wash. Proc. 11: 189, 1897 (type, Sciurus 
lateralis Say). 

Ictidomoides Mearns, U. S. Natl. Mus. Bull. 56: 328, 1907 (type, Sciurus mexi- 
canus Erxleben). 

Urocitellus Obolenskij, Comp. Rend. Acad. Sci. URSS., p. 188, 1927 (type, 
Spermophilus eversmanni Lichtenstein), 

HISTORY AND NOMENCLATURE 

The ground squirrel of central Europe — the ziesel — was mentioned 
in literature as early as 1551, by Konrad Gesner (p. 835), his account 
being the principal basis of the Linnaean name 3Ius citelh(s, the type 
of the genus Citellus. 

GENERIC AND SUBGENERIC NAMES 

The ground squirrels were referred by most of the earl}^ naturalists 
to the genus Arctomys { = Marmota)\ the name Spermophilus was 
proposed for the group by Cuvier in 1825, but it did not come into 
general use until about 5 years later. The earlier name Citellus. of 
Oken (1816), was overlooked until revived by Allen in 1902 (p. 373) ; 
&ince then it has been in current use. Rafinesque (1817, p. 45) intro- 
duced the name Anisonyx^ but it was not used by later authors until 
revived for a short time by Merriam (1895a, p. 18) , and later the same 
year was found to be preoccupied (Merriam, 1895b, p. 107), 

The rock squirrels were separated by Brandt (1844, p. 379) as a 
subgenus — Otospermophilus — and they have been regarded since 
1907 as a genus by Mearns and certain other writers. 

53 



54 NORTH AMERICAN FAUNA [No. 56 

In the same paper, Brandt proposed the subgenus Colobotis to 
inckide all the Old World species known to him and also richard- 
sonii, ^'■hoodW^ { = tridecemlineatus) , and franhlinii of North Amer- 
ica. The type is Spermo'philus fulvus Lichtenstein, of southern Kus- 
sia. The name Golohotis has been used in a subgeneric sensa by 
several modern authors without any definite idea of its correct ap- 
plication, due to the lack of material representing the type species. 
Eecently, through the kindness of L. R. Dice, opportunity has been 
afforded to examine a single skull of Citellus fulvus (pis. 14, 17, 20) 
from Turkestan (no. 57827, Univ. Mich. Mus. ZooL), and this proves 
to agree in essential characters with Citellus parryii ablusus, and so 
far as can be determined from a single specimen it does not differ in 
any character of generic value from O. citellus, the type of the genus. 

The only character of importance distingushing the skull of Citel- 
lus fulvus from that of C. citellus (pis. 14, 17, 20) appears to be the 
presence on the former of a well-defined metaloph on m^ ; this loph is 
absent on the series of 12 adult skulls of C. citellus from Hungary, 
but is faintly developed on a single young individual from the same 
region. Unfortunately, no young skulls of C. fulvus are available, 
and it is quite possible that the metaloph of m^ may vary in the ex- 
tent of its development, as it does in numerous North American 
species. 

Of the North American species, those in which the metaloph on 
m^ is most strongly developed are C. pa7'ryii, C. osgoodi, G. columhi- 
anus, G. richardsonii, C. armatus, and G. ivashingtoni. In G. town- 
sendii molUs and G. idahoensis, this loph is absent or very slightly 
developed, while in C. heldingi it is sometimes present, sometimes 
absent. 

In consideration of the great variability of tliis character in the 
American species, and in the absence of any definite group charac- 
ters, it is considered inadvisable to recognize Colobotis as a subgenus. 

Allen (1877, p. 821) established the subgenus Ictidomys, but with- 
out naming a type; Merriam (Allen, 1895a, p. 418) fixed the type as 
Citellus tridecemlineatus. Merriam (1892, p. 27) already had es- 
tablished the subgenus Xerospermophilus, with Spermophilus mo- 
havensis as type, and the subgenus Ammos'permophilus for the 
antelope ground squirrels, using as type, SpermopMlus leucurus. The 
latter group since 1905 has been accorded generic rank by most au- 
thors. In the present study it is again reduced to subgeneric rank, 
as is also Callospennophilus, proposed by Merriam in 1897 (p. 189) 
as a subgenus to include the mantled ground squirrels, and since 
regarded as a genus by many authors. 

Mearns (1907, p. 328) proposed the name Ictidomoides as a sub- 
genus for the species Citellus mexicanus, but this is now considered 
the same as Ictidomys. 

Obolenskij (1927, p- 188) has proposed Urocitellus as a subgenus, 
with C. eversinanni as the type, but this species shows no cranial 
characters to separate it from typical Citellus. 

The first two North American species to be recognized were Citel- 
lus mexicanus and C. variegatus^ both described by Erxleben in 1777, 
and referred to the genus Sciurus. The former name was adopted 
by later writers, but the latter was allowed to lapse, through failure 
to distinguish the animal to which it was applied, for more than a 



1938] REVISION OF THE GROUND SQUIRRELS 55 

century, when Nelson (1898, p. 898) reinstated it by showing its ap- 
plicability to the Mexican rock squirrel, then commonly referred 
to under the name Spermo'philus Tnacrourus. 

A similar fate was in store for the Columbian ground squirrel, 
fii-st described by Lewis and Clark and named Arctomys columbianus 
in 1815 by Ord (pp. 292, 303), and again in 1817, Anisonyx hrachi- 
ura, by Kafinesque (p. 45). Baird (1875, p. 336) discussed the pos- 
sibility that this animal might be a prairie dog — the same as his 
Cynomys gunnisoni — but he pointed out certain important differ- 
ences. Allen, however (1877, p. 903), unhesitatingly pronounced it a 
prairie dog and it was so considered until Merriam (1891, p. 39), 
having procured specimens from the type region, showed it to be a 
ground squirrel. 

The next species to be described was the striped ground squirrel, 
named Sciurus tridecemllneatus by Mitchill in 1821. The following 
year. Sabine renamed this animal hoodii and described also two other 
species, the Franklin's and Richardson's ground squirrels, all re- 
ferred by him to the genus Arctomys. 

Long's expedition to the Rocky Mountains in 181^20 resulted in 
the discovery of two new species, Citellus grammurus and G. lateralis, 
both described by Say in 1823 in the genus Sciurus. 

Richardson, in 1825, described the big northern ground squirrel, 
O. parryii, in the genus Arctomys, and in 1829, two supposed new 
varieties of that species, erythrogluieia and phaeognatha; erythro- 
gluteia later proved to be a synonym of columbianus and phaeog- 
natha a synonym of parryii. The same year he named two species 
from the west coast region, heecheyi and douglasii. 

In 1833, Bennett described the Mexican spotted ground squirrel, 
C. spilosoma, and the Mexican rock squirrel under the name Spermo- 
philus macrourus ; the latter name, however, was later found to be a 
synonym of C. variegatus. 

Bachman, in 1839, described Citellus toionsendii from the plains 
of the Columbia, but the type specimen soon became so discolored 
with grease that its true characters could not be seen, and as a result 
the name townsendii has been misapplied by most recent authors (see 
explanation on p. 62). 

Audubon and Bachman, in 1842, described Spermophilus {^Citel- 
lus) annulatus, and in 1854, S. harrisii — both from unknown locali- 
ties — and in 1855, Baird added S. couchii from northern Mexico. 

Thus, when Baird's monograph appeared in 1857, there had been 
described 16 valid races of ground squirrels from North America, 
and of these all but three were treated in the monograph. Spermo- 
philus annulatus was thought to be an African species of Sciurus; S. 
macrourus of Bennett {^Citelhis variegatus) was provisionally in- 
cluded, while Ord's Arctomys columhianus was doubtfully referred 
to as a prairie dog. Baird added in this paper one new species — the 
round-tailed spermophile of the Southwest — Spermophilus tereti- 
caudus. 

In 1861, Ross named a form of Parry's spermophile, Arctomys 
Icennicottii (not now recognized), and Slack described the black rock 
squirrel of Texas, Spermophilus hucMeyi. Kennicott, in 1863, de- 
scribed four new forms, all of which are now recognized as valid: 
Spermophilus mollis, S. armatus, S. elegans, and S. obsoletus. 



56 NORTH AMERICAN FAUNA [No. 56 

J. A. Allen added Speniiophilus parryii hodiacensis in 1874 and S. 
tridecemlineatus paUidus in 1877. In his Monograph of the Rodentia 
(1877) 17 forms were treated, only three more than appeared in 
Baird's monograph issued 20 years earlier. Spermophilus townsendii 
was considered to be a variety of Hchardsonii, whereas elegans and 
armatus were both listed in the synonymy of that species. Parry's 
spermophile appeared under the name of S. empetra, while S. har- 
risii and S. lateralis were transferred to the genus Tamias. 

No more new species were described until 1888, when Merriam 
named Spermophilus heldingL Shortly after this, the modern period 
of activity in systematic mammalogy began, initiated largely by the 
extensive researches and explorations of Merriam and his collectors 
in the Biological Survey. At the beginning of this period, 1889, 
30 forms of North American ground squirrels had been named, of 
which 25 are now considered valid races. Since that time, 91 addi- 
tional forms have been named, of which 69 are considered valid ; three 
new races are named in the present paper, making a total of 97 
recognized races. 

Key to Subgenera 

a\ Molars relatively hypsodont; parastyle ridge on m^ and m^ 
joining the protocone with an abrupt change of direction. 

6\ Metaloph on pm* continuous Citellus (p. 59) 

6^ Metaloph on pm* not continuous Ictidomys (p. 106) 

c^ Molars relatively braehydont : parastyle on m* and m* 
rising evenly to join the protocone, without abrupt change 
of direction. 
6\ Anterior upper premolar simple ; less than one-fourth the 
size of pm*. 
c^. Upper incisors relatively stout and distinctly recurved. 
<Z\ Brain ease rounded on upper surface. 

e\ Supraorbital foramen open Otospermophilus (p. 135) 

e^ Supraorbital foramen closed Notocitellus (p. 162) 

d^. Brain case flattened on upper surface Ammospemiophilus (p. 166) 

c". Upper incisors relatively slender, not distinctly recurved. 
d\ Postorbital processes long and slender ; rostrum 

longer CallospermopMlus (p. 190) 

d"^. Postorbital processes short and stout ; rostrum 

shorter Xerospermophilus (p. 183) 

&^ Anterior upper premolar bearing two cusps and a fimc- 
tional cutting edge ; more than one-fourth the size 
of pm* Poliocitellus (p. 133) 

List of Species and Subspecies, with Type Localities 
Subgenus CITELLUS Oken 

citellus townsendii gkoup 

Citellus townsendii townsendii (Bachman) Columbia River, near mouth of 

Walla Walla River, Washing- 
ton. 

townsendii canus (Merriam) Antelope, Oregon. 

townsendii vigilis Merriam Vale, Oregon. 

townsendii mollis (Kennicott) Camp Floyd, near Fairfield, 

Utah. 

townsendii artemesiae Merriam Birch Creek, Idaho. 

idahoensis (Merriam) Payette, Idaho. 



1938] REVISION OF THE GROUND SQUIRRELS 57 



CITELLUS WASHINGTONI GROUP 

Citellus washingtoni washingtoni, nobis Toucliet, Washington. 

washingtoni loringi, nobis Douglas, Washington. 

brunneus Howell New Meadows, Idaho. 

CITELLUS RICHARDSONII GROUP 

Citellus richardsonii richardsonii (Sabine) Carlton House, Saskatchewan. 

richardsonii elegans (Kennicott) Fort Bridger, Wyoming. 

richardsonii nevadensis 'H.oviell Paradise, Nevada. 

armatus (Kennicott) Fort Bridger, Wyoming. 

beldingi beldingi (Merriam) Donner, California. 

beldin'gi oregonus (Merriam) Swan Lake Valley, Oregon. 

CITELLUS PARRYII GROUP 

Citellus columbianus columbianus (Ord) Camas prairie, between the forks 

of the Clearwater and Koos- 
kooskie Rivers, Idaho. 

columbianus ruficaudus B.OTvel\ Wallowa Lake, Oregon. 

parryii parryii {Rich&Tdson) Lyon Inlet, Melville Peninsula, 

Canada. 

■parryii barrowensis (Merriam) Point Barrow, Alaska. 

parryii plesius (Osgood) Bennett City, British Columbia. 

parryii ablusus Osgood Nushagak, Alaska. 

parryii nebulicola Osgood Nagai Island, Shumagin Islands, 

Alaska. 

parryii lyratus Hall and Gilmore St. Lawrence Island, Alaska. 

kodiacensis (Allen) Kodiak Island, Alaska. 

osgoodi (Merriam) Fort Yukon, Alaska. 

Subgenus ICTIDOMYS Allen 

CITELLUS TRIDECEMLINEATUS GROUP 

Citellus tridecemlineatus tridecemlineatus (Mit- 

chill) Central Minnesota. 

tridecemlineatus texensis (Merriam) Gainesville, Texas. 

tridecemlineatus arenicola Howell Pendennis, Kansas. 

tridecemlineatus pallidus (Allen) Yellowstone River (mouth), Mon- 
tana. 

tridecemlineatus alleni (Merriam) Bighorn Mountains, Wyoming. 

tridecemlineatus hollisteri Bailey Sacramento Mountains, New 

Mexico. 

tridecemlineatus monticola Howell White Mountains, Arizona. 

tridecemlineatus parvus {Ml&u) Uncompahgre Indian Reserva- 
tion, Utah. 

mexicanus mexicanus (Erxleben) Toluca, Mexico. 

mexicanus parvidens (Mearns) Fort Clark, Texas. 

CITELLUS SPILOSOMA GROUP 

Citellus spilosoma spilosoma (Bennett) Durango, Mexico. 

spilosoma pallescens Howell La Ventura, Coahuila. 

spilosoma canescens (ISIerriam) Willcox, Arizona. 

spilosoma major (Merriam) Albuquerque, New Mexico. 

spilosoma annectens (Merriam) Padre Island, Texas. 

spilosoma pratensis iMeTTiam) San Francisco Mountain, Ari- 
zona. 

spilosoma cryptospilotus (Merriam) Painted Desert, Arizona. 

spilosoma obsoletus (Kennicott) Western Nebraska. 

perotensis (Merriam) Perote, Veracruz. 

Subgenus POLIOCITELLUS, nobis 

Citellus franklinii (Sabine) Carlton House, Saskatchewan. 



58 NORTH AMERICAN FAUNA [No. 56 

Subgenus OTOSPERMOPHILUS Brandt 

Citellus variegatus variegatus (Erxleben) Valley of Mexico, Mexico. 

variegatus rwpestris Allen Rio Sestin, Durango. 

variegatus couchii (Baird) Santa Catarina, Nuevo Leon. 

variegatus buckleyi (Slack) Packsaddle Mountain, Texas. 

variegatus grammurus (Say) Purgatory River, Colorado. 

variegatus tularosae "Qqhsovl Carrizozo, New Mexico (12 mi. 

northwest) . 

variegatus utah Merriam Ogden, Utah. 

beecheyi beecheyi (Richardson) San Francisco and Monterey, 

California (neighborhood of). 

beecheyi douglasii (Richardson) Lower Columbia River, Oregon, 

beecheyi sierrae, nobis Lake Tahoe, California. 

beecheyi fisheri (Merriam) Onyx, California. 

beecheyi parvulus Howell Argus Mountains, California. 

beecheyi nudipes Huey Hanson Laguna, Baja California. 

beecheyi rwpinarum Huey Catavina, Baja California. 

beecheyi nesioticus Elliot Catalina Island, California. 

atricapillus (Bryant) Comondii, Baja California. 

Subgenus NOTOCITELLUS, nobis 

Citellus annulatus annulatus (Audubon and 

Bachman) Manzanillo, Colima. 

annulatus goldmani (Merriam) Santiago, Nayarit. 

adocetus Merriam La Salada, Michoacan. 

Subgenus AMMOSPERMOPHILUS Merriam 

Citellus harrisiiharr isii(Auduhonand'Bsichin.a,ii). Santa Cruz Valley, Arizona. 

harrisii saxicola (Mearns) Tinajas Altas, Arizona. 

leucurus leucurus (Merriam) San Gorgonio Pass, California. 

leucurus tersus (Goldman) Prospect VaUey, Grand Canyon, 

Arizona. 

leucurus cinnamomeus (Merriam) Painted Desert, Arizona. 

leucurus pennipes (Howell) Grand Junction, Colorado. 

leucurus peninsulae (Allen) San Telmo, Baja California. 

leucurus canfieldae (Huey) Punta Prieta, Baja California. 

leucurus extimus (Nelson and Goldman) __ Saccaton, Baja California. 

interpres (Merriam) El Paso, Texas. 

insularis (Nelson and Goldman) Espiritu Santo Island, Baja Cali- 
fornia. 
nelsoni (Merriam) Tipton, California. 

Subgenus XEROSPERMOPHILUS Merriam 

Citellus mohavensis (Merriam) Hesperia, California (15 mi. east) . 

tereticaudus tereticaudus (Baird) Old Fort Yuma, California. 

tereticaudus neglectus (Merriam) Dolan Spring, Arizona. 

tereticaudus chlorus Elliot Palm Springs, California. 

tereticaudus apricus Huey Trinidad Valley, Baja California. 

Subgenus CALLOSPERMOPHILUS Merriam 

Citellus lateralis lateralis (Say) Canon City, Colorado. 

lateralis wortmani (Allen) Bitter Creek, Wyoming. 

lateralis arizonensis (Bailey) San Francisco Mountain, Ari- 
zona. 

lateralis caryi (Ro-'nqW) Wind River Mountains, Wyo- 
ming. 

lateralis cinerascens (Merriam) Helena, Montana. 

lateralis tescorum (Hollister) Smoky River (head), Alberta. 

lateralis castanurus (Merriam) Park City, Utah. 

lateralis chrysodeirus (Merriam) Fort Klamath, Oregon. 

lateralis connectens (Howell) Homestead, Oregon. 

lateralis trepidus (Taylor) Pine Forest Mountains, Nevada. 



1938] REVISION OF THE GROUND SQUIRRELS 59 



CiteUvs lateralis cerius (Goldman) Charleston Peak, Nevada. 

lateralis bernardinus (Merriam) San Bernardino Peak, California. 

lateralis mitraius (Howell) South Yolla Bolij^ Mountain, 

California. 

lateralis trinitatis (Merriam) Trinity Mountains, Cahforuia. 

saiurafus (Rhoads) Lake Keechelus, Washington. 

madrensis (Merriam) Sierra Madre, Chihuahua. 

Explanation of Cranial, Measueements 

Measurements of the skulls of Citellus have been taken in millimeters, as 
follows : 

Qreatest length. — From anterior border of nasals to posterior border of supra- 
occipital in median line. 

Palatilar length. — From posterior border of upper incisors to posterior border 
of palate (disregarding median process). 

Zygomatic breadth. — Greatest breadth across zygomata. 

Cranial breadth. — Least breadth of cranium measured just behind the 
-zygomata. 

Interorbital breadth. — Least breadth across froutals in front of postorbital 
processes. 

Postorbital constriction. — Least breadth across frontals behind postorbital 
processes. 

Length of )iasals. — Greatest length of nasals, measured along median line. 

Maxillary tooth row. — Alveolar length of maxillary molar-premolar tooth row. 

Subgenus CITELLUS Oken 

[For subgeneric cbaracters, see p. 40] 

Key to Species and Subspecies 

a\ Upper parts unspotted. 

6\ Hind foot more than 39 mm. 

c\ Under side of tail grayish armatus (p. 78) 

c^. Under side of tail huffy or reddish. 
d\ Under side of tail huffy. 

e\ Upper parts more buffy r'lchardsonii (p. 73) 

€^. Upper parts more grayish elegans (p. 76) 

ri^ Under side of tail reddish. 

e\ Upper parts mainly reddish beldingi (p. 81) 

e^ Upper parts mainly grajdsh. 

f. Under side of tail hazel ' oregonus (p. 83) 

f. Under side of tail sayal brown nevadensis (p. 77) 

6^ Hind foot less than 39 mm. 

c^. Size large (average length about 24(5 mm) ; upper parts 

dappled iduhoensis (p. 68) 

c*. Size smaller (average length about 226 mm) ; upper parts 
plain. 

d\ Size smaller (skull length, 32.4-35.3) artemesiae (p. 65) 

d-. Size larger (skull length, 34.6-39.6). 
e\ Upper parts mainly grayish. 

f. Tail longer (44-61 mm) mollis (p. 63) 

f. Tail shorter (37-42 mm) canus (p. 67) 

e^. Upper parts mainly buffy. 

f. Skull larger (37..3-39.6 mm) ; color paler vigilis (p. 66) 

f. Skull smaller (37-38.7 mm) ; color darker townsendii (p. 60) 

o'. Upper parts spotted or mottled. 

b^. Size larger (hind foot more than 40 mm). 
c\ Dorsal spots whitish. 

d^ Hind feet darker (hazel) osgoodi (p. 104) 



go NORTH AMERICAN FAUNA [No. 56 

al Upper parts spotted or mottled — Continued. 

&\ Size larger (hind foot more than 40 mm) — Continued. 
c\ Dorsal spots whitish — Continued. 

d"^. Hind feet paler (cinnamon, buff, or clay color). 

e\ Tail shorter (77-82 mm) nebuUcola (p. 100) 

el Tail longer (81-138 mm). 
f. Dorsal spots smaller. 

g^. Tail darker (more blackish) above, paler be- 
neath kodiacensis (p. 103) 

g^. Tail paler above, darker beneath plesius (p. 97) 

f. Dorsal spots larger. 

g^. Under parts darker in summer pelage (ochraceous 

tawny) parryii (p. 91) 

g^. Under parts paler in summer pelage (cinnamon 
bufe). 
h^. Size larger (skull length, 58-62.8 mm)_ larroivensis (p. 95) 
h". Size smaller (skull length, 54-58.8 mm). 

t\ Upper parts brownish ailusus (p. 98) 

f. Upper parts grayish lyratus (p. 101) 

(f. Dorsal spots buffy. 

d\ Tail mainly grayish above columbianus (p. 85) 

d^. Tail mainly reddish above ruflcaudus (p. 89) 

6l Size smaller (hind foot less than 40 mm), 
c^. Upper parts grayish. 

d^. Size larger (hind foot, 34-38 mm) washingtoni (p. 69) 

d\ Size smaller (hind foot, 30-33 mm) loringi (p. 71) 

cl Upper parts brownish hrunneus (p. 72) 

CITELLUS TOWNSENDII GROUP 

CITELLUS TOWNSENDII (Bachman) 

[Synonymy under subspecies] 

SpecifiG characters. — Size small; hind foot 29-36 mm; tail 32-61; 
skull length 32.'^39.6. Skull relatively short and broad; zygomata 
heavy and rather widely expanded; rostrum stout, its sides nearly 
parallel ; supraorbital borders slightly elevated ; postorbital processes 
long, slender, decurved; brain case broad; temporal ridges lyrate, 
meeting posteriorly in old age to form a slight crest ; audital bullae 
moderately inflated, the meatus rather long; molars hypsodont; upper 
incisors rather slender. Coloration plain, smoke gray, shaded with 
pinkish buff or pinkish cinnamon ; tail cinnamon drab, sayal brown, 
or clay color. 

CITELLUS TOWNSENDII TOWNSENDII (Bachman) 

TOWNSEND'S GEOtrND SQUIEEEIi 

Spernwphilus townsendii Bachman, Jour. Acad. Nat. Sci. Phila. 8: 61, 1839; 

Townsend, Narr. Jour. Rocky Mountains to Columbia River, etc., p. 316, 1839. 
Spennophilus mollis yakimensis Merriam, Biol. Soc. Wash. Proc. 12: 70, Mar. 

24, 1898. 
[Gitellus mollis] yakimensis Trouessart, Cat. Mamm., Sup., p. 339, 1904. 

Type. — Collected "on the Columbia River, about 300 miles above 
its mouth" [near the mouth of Walla Walla River, Wash.], in July 
1836, by J. K. Townsend ; mounted specimen no. 344, collection Acad. 
Nat. Sci. Philadelphia. 

Range. — South-central Washington, between the Columbia River 
and the Cascade Range, north to EUensburg (fig. 1). Zonal range: 
Upper Sonoran. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



61 



External characters. — Similar in color to G. t. canus and C. f. 
vigilis but averaging more buffy or brownish (less grayish) above; 
tail and hind feet longer than in canus. 

Cranial characters. — Skull similar to that of canus but averaging 
longer (actually and relatively), with decidedly longer nasals and 
tooth row, and larger audital bullae. 

Color. — Winter felage (March) : Upper parts smoke gray, shaded 
with pinkish buff; patch on front of face cinnamon; sides of face 
and head smoke gray; sides of body faintly washed with pinkish 




FiGUUE 1.^ — Distribution of the subspecies of Citellus toicnsendii: 1. C. t. totcnsendU; 
2, C. t. canus; 3, V. t. vigilis; 4, C. t. artemesiae ; 5, V. t. mollis. 

buff; thighs cinnamon; feet pinkish buff; tail cinnamon or sayal 
brown, shaded with fuscous and edged with buffy Avhite or pinkish 
butt"; under parts creamy white, washed with pinkish buff. ^Vo7'n 
summer pelage (July 16) : Paler and more grayish than in winter 
and not appreciably different from canus at that season. 

Variation. — A single specimen in a series of 14 taken in ISIarch 
at Ellensburg and Yakima is decidedly darker than the rest, the 
upper parts being uniform pale snuff' brown. 

Measurements.'^ — Average of 10 adults from Mabton and North Yakima, 
Wash.: Total length, 212.2 (200-2:^2); tail vertebrae, 45.7 (39-54); hind 
foot, 3.3.9 (32-37). SkuU: Average of 10 adults from Mabton, Bickleton, and 
North Yakima: Greatest length, 37.9 (37.1-38.7) ; palatilar length, 17.9 (17.3- 
18.2) ; zygomatic breadth, 24 (23.3-25.1) ; cranial breadth 17.9 (17.-JH8.4) ; 



•All measurcmenta are in millimeters (see p. 59). 



62 NORTH AMERICAN FAUNA [No. 56 

interorbital breadth, 7.5 (7-8.2) ; postorbital constriction, 10.3 (9.4-10.9) ; 
length of nasals, 14.5 (13.2-15.7) ; maxiUary tooth row, 8.2 (8-8.5). 

Remarks. — This species, although first recognized nearly 100 years 
ago, remained imperfectly known for most of that period and at the 
present time the name townsendii is currently applied to another 
species (here described under the name Gitellus washingtoni) . The 
type specimen was collected by J. K. Townsend, "on the Columbia 
Kiver, about 300 miles above its mouth, in July" 1836 (Townsend, 
1839, p. 316). Bachman (1839, p. 61), in the original description, 
states that Townsend informed him that the species inhabits "the 
prairies near the Walla- walla." It so happens that in the section 
alon^ the Columbia River at the mouth of the Walla Walla River two 
species of ground squirrels occur — a plain-colored form on the west 
side of the river and a spotted species on the east side. Townsend 
does not state on which side of the river his specimen was taken. 

Fortunately, the type specimen has been j)reserved in the collection 
of the Academy of Natural Sciences of Philadelphia (no. 344), and 
through the courtesy of the authorities of that institution the writer 
has been able to examine and compare it with modern specimens. 
The type specimen had been mounted with the skull inside and in 
the course of years it has become so covered with grease and dirt as 
to be almost unrecognizable. After being immersed for several days 
in petroleum ether, however, the grease has largely been removed 
and the animal is seen to lack the conspicuous buffy white spots of 
the species living on the east side of the Columbia, currently known 
under the name Gitellus townsendii. 

A brief review of the history of this name will assist in clearing 
up the misunderstanding as to its allocation. In the original descrip- 
tion no mention is made of dorsal spotting, but in Audubon and 
Bachman (1854, p. 226) the description of this species includes a 
statement that it is "speckled with white all over the back." This, 
however, apparently does not mean that it is spotted, for on page 
228 the authors say that they compared a specimen with the Euro- 
pean Spermophilus guttatus — a coarsely spotted species — and found 
it very different. "They may be distinguished from each other at 
a glance by the large rounded spots on the back of the Russian ani- 
mal, compared with the white and irregular specks in the American 
species." 

J. A. Allen, in a paper listing the species and varieties of the North 
American Sciuridae (1874, p. 293), correctly associated townsendii 
with Spermophilus mollis^ but in his monograph of the group ( 1877, 
pp. 84&-854) he transferred the name to the form described by Ken- 
nicott in 1863 as S. elegans^ listing it as a variety of S. richardsoni. 

Merriam (1891, p. 36) showed that Allen's assignment of the name 
to elegans was wrong, and applied it to the small unspotted ground 
squirrel of southern Idaho, listing S. mollis as a possible subspecies 
of the same group. 

Twenty-two years later (1913, p. 137) Merriam described this 
Idaho race under the name G. mollis artemesiae, but failed to asso- 
ciate it with townsendii, as he had previously done. 

In May 1891 a collector from the Biological Survey obtained a 
series of the spotted ground squirrels from Pasco and Touchet, 



1938] REVISION OF THE GROUND SQUIRRELS 63 

Wash., and on the assumption that they came from the type region 
of towThsendii, they were referred to that species and so labeled in 
the Biological Survey collection. Now, however, since the type speci- 
men of townsendii proves to be unsj)otted, and agrees in size and 
general coloration with the species living on the west side of the 
Columbia River, it becomes necessary to transfer the name town- 
sendii to that race now known as Gitellus mollis yakimensis. 

This race is apparently isolated by the Columbia River from the 
other races of townsendii; it is most nearly related to canus but is 
decidedly more brownish, especially in winter pelage. Contrary to 
the usual condition in this group the winter pelage is more brownish 
(less grayish) than the summer pelage. 

/Specimens examined. — Total number, 33, as follows: 

Washington: Bickleton, 3; Columbia River Valley (20 miles south of Priest 
Rapids), 1; EUensburg, 8; Kiona (Benton County), 2;' Mabton, 9; North 
Yakima, 3 ; Wiley City, 6 ; Yakima, 1.' 

CITELLUS TOWNSENDII MOLLIS (Kennicott) 

Piute Ground Squirrel 

(Pis. 1; 23, A; 28, A) 

Spertnophilus mollis Kennicott, Acad. Nat. Sci. Phila. Proc. 1863 : 157. 

[Spermophilus townaendi] var. mollis Allen, Boston Soc. Nat. Hist. Proc. 16: 
293, 1874. 

Spermophilus mollis stephensi Merriam, Biol. Soc. Wash. Proc. 12: 69, 1898. 
(Queen Station, near head of Owens Valley, Nev.) 

[Citellusl mollis Trouessart, Cat. Mamm., Sup., p. 339, 1904. 

Citellus leurodon Merriam, Biol. Soc. Wash. Proc. 26: 136, 1913. (Murphy, 
Idaho.) 

Citellus mollis washoensis Merriam, Biol. Soc. Wash. Proc. 26: 138, 1913. (Car- 
son Valley, Nev.) 

Type. — Collected at Camp Floyd, near Fairfield, Utah, March 18, 
1859, by C. S. McCarthy ; skin and skull, no. ^^ , U. S. Natl. Mus. 
(orig. no. 164.) 

Range. — Western Utah, southern Idaho, Nevada, and southeastern 
Oregon; north to Pocatello and Weiser, Idaho, and Rome, Oreg.; 
east to Salt Lake City and Manti, Utah ; south to Cedar City, Utah, 
and Clark County, Nev. ; west to Carson, Nev., and Honey Lake and 
Owens Valley, Calif, (fig. 1). Zonal range: Upper Sonoran. 

External characters. — Smaller and paler than G. idahoensis; color 
plain smoke gray, without distinct dappling; tail paler and less 
bushy. 

Cranial characters. — Skull about the size of that of C. washingtoni 
washingtoni; in comparison with that of the other races of C. town- 
sendii., relatively long and narrow, the zygomata not wide spreading ; 
rostrum and nasals long, the nasals ending posteriorly on a line with 
the premaxillae or beyond them. 

Color. — Gray phase (Fairfield, Utah, June 28) : Upper parts uni- 
form smoke gray (a subterminal band of snuif brown or bister on 
the body hairs, in worn pelage, lends a brownish cast to the general 
tone, with a suggestion of "dappling") ; nose and front of face cin- 
namon or clay colDr; sides of head and body often more or less 
washed with pinkish buff; eyelids creamy white or pinkish buff; 

^ Univ. Michigan Mu8. Zool. 



g4 NORTH AMERICAN FAUNA [No. 56 

front feet pinkish buff; hind feet grayish white, sometimes washed 
with pinkish cinnamon; thighs usually strongly washed with pink- 
ish cinnamon; tail above and below smoke gray, strongly shaded 
with cinnamon or snuff brown, especially on distal portion, and 
edged with white; under parts creamy white, washed with pinkisli 
buff. Buff phase: Similar to the gray phase biit entire upper parts 
strongly washed with pinkish buff. 

Molt. — In the series examined there is no clear indication of when 
or how the molt takes place ; numerous specimens taken in the latter 
half of May and early in June are in badly worn pelage, which 
would indicate that the molt may occur in June or July. 

Measurements. — Average of 12 (ad. and subad.) from Fairfield, Utah: Total 
length, 213.1 (201-233) ; tail vertebrae, 52 (4-^61) ; hind foot, 33.7 (31-36). 
Skull: Average of 15 (ad. and subad.) from Fairfield, Nephi, Salt Lake City, 
and Promontory, Utah: Greatest length, 37.5 (36.1-39.3) ; palatilar length, 18.2 
(17-19) ; zygomatic breadth, 23.8 (22.7-25.7) ; cranial breadth, 17.4 (16.4-18.5) ; 
interorbital breadth, 7.7 (6.5-8.5) ; postorbital constriction, 10 (9.2-10.7) ; length 
of nasals, 13.2 (12.6-14.4) ; maxillary tooth row, 8.2 (7.5-8.5). 

Weight. — Two females from White Horse Sink, Oreg., weighed 8 ounces each. 

Remarks. — The Piute ground squirrel is widely distributed in 
the Great Basin and has been known for many years. In southeast- 
ern Idaho it grades into the smaller race G. t. artemesic.e. A single 
specimen from Disaster Peak, Oreg., agrees with mollis in color but 
in skull characters resembles C. t. canus. 

A considerable series from southern Nevada, including topotypes 
of the form ''''stephensi''\ prove to be not appreciably different from 
typical mollis. 

The form described from Murphy, Idaho, under the name 
Heurodon''' seems clearly referable to typical mollis; the skull of 
the type may be closely matched by specimens from Utah, and the 
average skull measurements of a series of Heurodon''' show no im- 
portant differences by which they could be separated from mollis. 

The form described from Carson Valley, Nev., as ^hvashoensis" is 
slightly darker than typical mollis; the skull of the type is from a 
very old and abnormally large individual, but that of another adult 
male in the series is closely matched by specimens of mollis from 
Salt Lake City, Utah; therefore, ^^ivashoeiisis^^ is placed in the syn- 
onymy of mollis. Specimens from Pyramid Lake, Wadsworth, Still- 
water, and Smoke Creek are typical of mollis. 

Specimens examined. — Total number, 249, as follows : 

California: Amedee, 1 ;' Honey Lake, 3 ;* Horse Lake (Lassen County), 1 ; Karlo 
(Lassen County), l;VLong Valley (Mono County), 2; Mono Lake, 2;' 
Owens Valley, 6; Wendel (Lassen County), 2.* 

Idaho: American Falls, 6; Gooding, 1;^ Murphy, 7; Oakley, 1; Payette, 1; 
Pocatello 10: Rogerson, 1; Rupert, 1;* Weiser, 7. 

Nevada: Baker (White Pine County), 3;' Blair Junction (Esmeralda County), 
1;' Carlin, 1:° Carson, 13; Cave Spring (Esmeralda County), 1;^ Chiato- 
vich Ranch (Esmeralda County), 1;* Cloverdale (Nye Countv), 1; Elko, 3; 
Fish Lake Valley (Esmeralda County), 3;' Goldfield, 1;' Goshute Moun- 
tains, 1 ; Granite Creek (Washoe County) , 1 ; Halleck, 6 : Indian Creek (near 
head, Nye County), 2; Indian Spring (north slope Charleston Mountains), 
1;" Little High Rock Canyon (Washoe County), 1;' Metropolis, 2; Millett 
(Nye County), 1;* Monitor Valley (50 miles north of Belmont), 1; Mount 
Magruder ( = Sugarloaf Peak, Esmeralda County), 15; Nixon (Washoe 

sMus. Vert. Zool. 

^ Univ. Michigan Mus. Zool. 

10 D. R. Dickey coll. 



1938] REVISION OF THE GROUND SQUIRRELS g5 

County), 1; Osceola (White Pine County), 1;' Palmetto (Esmeralda 
County), 5;** Panaca (Lincoln County), 1;* Paradise, 1; Peavine Creek 
(Nye County), 4; Pine Forest Mountains (Big Creek Ranch), 4;' Pyramid 
Lake, 20; Queen (Mineral County), 6; Quinn River Crossing (Humboldt 
County), 17;' Reese River (Nye County), 4; Round Mountain (Nye 
County), 3; Steptoe Valley (9 miles south of Schellbourne), 1;* Silver Peak 
Mountains, 1; Smoke Creek (Washoe County), 6; Springdale (Nye County), 
4;^" Stillwater (Churchill County), 1; Summit (Esmeralda County), 1;'° 
Toyabe Range, 2; Virginia Mountains (Washoe Coimty), 1; Wadsworth, 3; 
White River Valley (15 miles southwest of Sunnyside), 1;' Whiterock 
Valley (30 miles southwest of Austin), 1; Winnemucca, 1; Winnemucca 
Lake, 1. 

Oregon: Disaster Peal<: (Malheur County), 1; Rome (Malheur County), 2; 
White Horse Sink (Harney County), about 16 miles east of Alvord Lake, 2. 

Utah: Cedar City, 9;"*=* Fairfield, 16; Kelton (Box Elder Coimty), 1;' Malone 
(Millard County), 1; Manti, 1; Midvale, 1; Modena (Iron County), 4; 
Nephi, 1 ; Promontory (Box Elder County), 4 ; Salt Lake City, 3. 

CITELLUS TOWNSENDII ARTEMESIAE Mekbiam 

LELiST Idaho Ground Squtrkei. 

Spennophilus townsendi Merriam, North Amer. Fauna 5: 36, 1891 (not of 

Bachman). 
Gitelliis mollis artemesiae Merriam, Biol. Soc. Wash. Proc. 26: 137, May 21, 1913. 
Citellus mollus [sic] pessimus Merriam, Biol. Soc. Wash. Proc. 26: 138, 1913 

(Big Lost River, Idaho). 

Type. — Collected on Birch Creek, about 10 miles south of Nicholia, 
Idaho, August 9, 1890, by Vernon Bailey; male adult, skin and skull, 
1^0- wtItj U. S. Natl. Mus. (Biological Survey collection) (orig. 
no. 1573). 

Range. — Southeastern Idaho, from southern Lemhi County south 
to the Snake River valley (fig. 1). Zonal range: Upper Sonoran. 

External characters. — Smallest of the races of 0. toionsendii; color 
slightly darker and more dappled than in C. t. mollis., tinged with 
brownish, and with less buff on sides of head and body. 

Cranial characters. — Skull decidedly smaller than that of mollis., 
with relatively shorter rostrum. 

Color. — Summer pelage (August) : Upper parts pale smoke gray, 
sometimes faintly washed with pinkish cinnamon ; nose and front of 
face cinnamon ; sides of neck and body only- faintly tinged M'ith pink- 
ish buff; front feet grayish white, washed with pinkish buff; hind 
feet grayish white; thighs cinnamon buff; tail above, cinnamon buff 
rnixed with fuscous and with a subterminal patch of fuscous black, 
tipped with grayish white; tail beneath, dull clay color or cinnamon; 
under parts creamy white, faintly washed with pinkish buff. 

Measurements. — Average of 7 adults from type locality: Total length, 179 
(167-188) ; tail vertebrae, 36.6 (32-43) ; hind foot, 29.7 (2<>-31). Skull: Aver- 
ago of 7 adults from typo locality: Greatest length, 33.5 (32.4-35.3) ; palatilar 
length, 16 (15.3-16.8) ; zygomatic breadth. 21.5 (21-23) ; cranial breadth, 16.3 
(15.6-17.1) ; interorbital breadth, 6.7 (6.4-7) ; po.storbital constriction, 9.8 (9.2- 
10.3) ; length of nasals, 12 (11.4-12.7) ; maxillary tooth row, 7.4. 

Remarks. — This small race of townsendii occupies a rather limited 
area in southeastern Idaho. The series from Big Lost River, which 
forms the basis of Merriam's ^^pessiinus^^ is intermediate in size between 

^•Mu.'i. Vert. Zool. 
»»D. R. Dickey coll. 
»E. R. Warren coll. 
12 Cleveland Mus. Nat. Hist. 
1.54970—38 5 



gg NORTH AMERICAN FAUNA tNo. 56 

mollis and arteinesiae but nearer to the latter. _ The specimens appear 
slightly darker than typical artemesme but this may be due to wear, 
and in any case the difference is too slight to warrant recognition of 
the form by name. 
Specimens examined. — Total number, 31, as follows : 

Idaho: Berenice (Butte County), 2;" Big Lost River, 10; Birch Creek, 7; 
Blackfoot, 7; Pingree (Bingham County), 2;" Taber (Bingham County), 
2;" Twin Lakes, Snake River Desert (20 miles north of Minidoka), 1. 

CITELLUS TOWNSENDII VIGILIS Meekiam 

Malhetjb Valley Gbottnd Sqtjireel 

Citellus canus vi gilts Merriam, BioL Soc. Wash. Proe. 26 : 137, May 21, 1913. 

Gitellus mollis vigilis Miller, U. S. Natl. Mus. Bull. 128 : 188, 1924. 

r^/^e.— Collected at Vale, Oreg. April 29, 1910, by Stanley G. 
Jewett; female adult, skin and skull, no. 168361, U. S. Natl. Mus., 
(Biological Survey collection) (orig. no. 30). 

Range. — Confined apparently to the lower part of Malheur Valley, 
Oreg., in the vicinity of Vale and Ontario and north in the Snake 
Eiver valley to Huntington. Zonal range: Upper Sonoran. 

External characters. — Largest of the races of G. townsendii; closely 
similar in coloration to G. t. canus., but averaging slightly more buffy ; 
darker (more buffy) than G. t. mollis. 

Granial characters. — Slmll similar to that of canus., but larger; 
averaging about the same length as that of mollis., but zygomata 
heavier and more widely spreading; rostrum relatively shorter and 
broader ; maxillary tooth row slightly shorter. 

Golor. — Worn tvinter pelage (April and May) : Upper parts smoke 
gray, sometimes faintly washed with pinkish cinnamon ; front of face 
with a rather extensive patch of cinnamon; sides of neck and body 
faintly (rarely strongly) washed with pinkish buff or pale pinkish 
buff ; front feet pinkish buff, hind feet creamy white ; tail above and 
below, cinnamon drab, mixed with fuscous, edged with white or buffy 
white, and with a subterminal patch of fuscous ; under parts creamy 
white, faintly washed with pinkish buff, the hairs fuscous at base, 
and this color often more or less prominent in mixture with the lighter 
tips. Summer pelage : Not represented. 

Measurements. — Average of 10 adults from Ontario and Vale, Oreg. : Total 
length, 226.2 (201-238) ; tail vertebrae, 44.4 (35-52) ; hind foot, 33.1 (31-35). 
Skull: Average of 13 adults from same localities: Greatest length, 38.3 (37.S- 
39.6) ; palatilar length, 18.4 (17.5-19.5) ; zygomatic breadth, 25.5 (24.5-26.7) ; 
cranial breadth, 17.8 (17.2-18.4) ; interorbital breadth, 7.9 (7.3-8.4) ; postorbital 
constriction, 9.6 (8.9-10.5) ; length of nasals, 13.4 (12.8-13.8) ; maxillary tooth 
row, 7.7 (7.2-8.2). 

Remarks. — ^Living in a rich, fertile valley this race has developed 
markedly in size and robustness of skull. Its range apparently is 
quite limited, since the specimens a few miles to the westward of 
Vale are referable to canus and those on the east side of Snake River 
to mollis. 

Specimens examined. — Total number, 53, as follows : 

Oregon : Huntington, 4 ; Ontario, 23 ; Vale, 26. 



13 Mus. Vert. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS 67 

CITELLUS TOWNSENDII CANUS (Merriam) 

Gray Ground Squikkel 

Spermophilus mollis canus Merriam, Biol. Soc. Wash. Proc. 12 : 70, Mar, 24, 1898. 
[Citellus mollis] canus Trouessart, Cat. Mamm., Sup., p. 339, 1904. 

Type. — Collected at Antelope, Wasco Comity, Oreg., June 21, 1896, 
by Vern6n Bailey ; female adult, skin and skull ; no. 78681, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 5561). 

Range. — Eastern Oregon and extreme northwestern Nevada ; north 
to Antelope; west to Warmspring, Bend, and Summer Lake; south 
to Summit Lake, Nev. ; east to Catlow Valley and Cedar Mountains, 
Oreg. (fig. 1). Zonal range: Upper Sonoran. 

External characters. — Closely similar in color to C. t. mollis; tail 
and hind feet shorter. Similar also to G. t. vigilis but smaller; 
cimiamon patch on face paler. 

Cranial characters. — Skull similar in shape to that of vigilis but 
smaller. Compared with mollis : Shorter and relatively broader, the 
zygomata more wide spreading; bullae averaging smaller; rostrum 
relatively short and broad. 

Color. — Summer pelage (June 20-July 14) : Upper parts smoke 
gray, often with a faint wash of pinkish cinnamon and frequently 
more or less darkened by exposure of the subterminal fuscous areas 
of the hairs ; patch on front of face pinkish cimiamon ; sides of face, 
neck, and body sometimes faintly shaded with pinkish buff; tail and 
feet as in vigilis. Worn lointer pelage: Practically as in summer. 
Immature pelage: Similar to the adult pelage but often strongly 
shaded on sides of head and body with pinkish buff or cinnamon 
buff. 

Measurements. — Average? of 10 adults from Antelope, Gateway, and Prineville, 
Oreg.: Total length, 201.4 (190-217); tail vertebrae, 39.4 (37-42); hind foot, 
30.7 (29-33). Skull: Average of 10 adults from Antelope and Gateway: Great- 
est length, 36.3 (34.6-38) ; palatilar length, 17.3 (16.5-18.5) ; zygomatic breadth, 
23.9 (23.1-24.5) ; cranial breadth. 17.(5 (17-18.2) ; interorbital breadth, 7.5 (7-8) ; 
postorbital constriction, 10.1 (9.3-11) ; length of nasals, 12.9 (12.2-13.6) ; maxil- 
lary tooth row, 7.4 (7-7.8). 

Remarks. — This small gray race occupies most of the desert valleys 
of eastern Oregon except the extreme southeastern part, intergrading 
with the larger vigilis in the extreme eastern part of the State and 
with mollis in southern Malheur County and in northwestern Nevada. 
There are no records of its occurrence in northern Oregon, north of 
Antelope. 

Specimens examined. — Total number, 97, as follows : 

Nevada: Hot Springs, Thousand Creek, 3;" Summit Lake (Humboldt County), 
1; Virgin Valley (Humboldt County), 3." 

Oregon: Antelope (7 miles east), 7; Baker (10 miles north), 3; ^' Barnes (Cook 
County), 1;" Bend, 11; Burns, 2; Cedar Mountains (Malheur County), 1; 
Christmas Lake (10 miles north), 1; Crane (Harney County), 6; Drewsey, 
2; Fremont, 1; Gateway (Jefferson County), 15; Haycreek (Jefferson 
County), 5; Malheur Lake, 1; Narrows, 17; Plush (Lake County), 1; Prine- 
ville. 6; Riverside (Malheur County), 1; Rock Creek (Harney County), 4; 
Summer Lake, 2; Warmspring (Jefferson County), 3. 



"Mus. Vert. Zool. 

1" Univ. Michigan Mus. Zool. 



68 



NORTH AMERICAN FAUNA 



[No. 56 



CITELLUS IDAHOENSIS Mekeiam 

Snake Valley Ground Sqxjieeel 

(Pls. 23, B; 28, B) 

Citellus idahoensis Merriam, Biol. Soc. Wash. Proc. 26 : 135, May 21, 1913. 

Type.— Collected at Payette, Idaho, April 23, 1910, by Stanley G. 
Jewett; female adult, skin and skull, no. 168290, U. S. Natl. Mus. 
(Biological Survey collection) (orig. no. IT). 

Range. — North side of Snake River Valley, Idaho, from Payette 
to Glenns Ferry (fig. 2). Zonal range: Upper Sonoran. 

External charac- 
ters. — Similar to C. 
townsendii mollis but 
larger ; tail longer, 
and more tawny; up- 
per parts slightly 
darker and more dis- 
tinctlj'^ dappled. Com- 
pared with C. richard- 
sonii elegans: Size 
smaller ; tail shorter 
and darker ; coloration 
more grayish (less 
brownish or buffy). 

Cranial charac- 
ters. — Skull similar to 
that of G. tow-nsendii 
vigilis, but averaging 
larger ; nasals and 
molariform tooth row 
longer ; similar also to 
that of mollis but de- 
cidedly larger; audi- 
tory meatus longer. 

Color. — U nworn 
lointer pelage (April) : 
Upper parts pale 
smoke gray, faintly or 
moderately shaded 
with pinkish buff or 
cinnamon buff, with a 
slight indication of 
mottling ; a basal zone of deep mouse gray on the back, succeeded by 
a zone of smoke gray and then by a subterminal band of fuscous. 
Patch on front of face sayal brown; sides of body faintly washed 
with pinkish buff; front feet pinkish buff; hind feet buffy whitish; 
tail above, mixed pinkish cinnamon and fuscous edged with bufl'y 
white and with a subterminal band of fuscous ; tail beneath, cinnamon 
or sayal brown ; under parts grayish white, faintly washed with pinlc- 
ish buff, the bases of the hairs fuscous. Worn winter pelage (June 
4) : General tone of upper parts pale snuff brown sprinkled with 
pinkish buff (the brownish tones due largely to exposure of the 
subterminal bands on the hairs). 




Figure 2. — ^Distribution of Citellus idahoensis. 



1938] REVISION OF THE GROUND SQUIRRELS gQ 

Measurements. — Average of 20 adults from Payette and Nampa, Idaho: 
Total length, 245.9 (222-271) ; tail vertebrae, 59.2 (46-72) ; hind foot. 35.6 
(33-38). Skull: Average of 16 adults from same localities: Greatest length, 
40.1 (37.7-43.3) ; palatilar length, 19.4 (18-21.2) ; zygomatic breadth, 25.9 
(25-26.8) ; cranial breadth, 18 (17-19) ; interorbital breadth, 8.2 (7.3-8.8) ; 
postorbital constriction, 9.7 (9-10.5) ; length of nasals, 14.3 (13.6-15.2) ; 
maxillary tooth row, 8.3 (7.8-9). 

Remarks. — G. idahoensis., although evidently belonging in the 
townsendii group, is clearly a distinct species, since it occurs in certain 
areas with C. t. mollis and maintains its characters without inter- 
gradation. It is best distinguished from C. t. mollis or 0. t. mgilis 
by its longer, broader, and more tawny tail, and by the more pro- 
nounced mottled effect on the upper parts. The skulls show ex- 
treme variation in size, and the smallest ones are scarcely distin- 
guishable from those of vigilis, though usually having a longer and 
heavier molar tooth row. So far as known, the species occupies a 
rather restricted range on the north side of the Snake River Valley 
in western Idaho. 

S'pecim.ens examined. — Total nimiber, 118, as follows: 

Idaho: Glenns Ferry, 3; Kuna (Ada County), 7; Mountain Home, 9; Nampa, 
67; Orchard (Ada County), 6; Payette, 26. 

CITELLUS WASHINGTONI GROUP 

CITELLUS WASHINGTONI, SP. Nov. 

[Synonymy under subspecies.] 

General characters. — About the size of C. toionsendii mollis^' hind 
foot, 30-38 mm ; tail, 32-65 ; skull length, 35-41.4. Skull similar to 
that of C. t. toionsendii but relatively longer and narrower; smaller 
and relatively narrower than those of G. idahoensis and G. hrunneus. 
Upper parts smoke gray, flecked with whitish spots; tail mixed 
fuscous and grayish white, with blackish tip. 

CITELLUS WASHINGTONI WASHINGTONI, subsp. nov. 

Washington Ground SQxnBREi. 

(Pis. 1 ; 23, C; 28, C) 

Citellus townsendii Dice, Jour. Mammal. 1 : 18, 1919 ; Bailey, North Amer. 
Fauna 55: 151, 1936 (not Spermophilus townsendii Bachman). 

Type. — Collected at Touchet, Walla Walla County, Wash., May 18, 
1891, by Clark P. Streator; male adult, skin and skull; no. |-^-|4, 
U. S. Natl. Mus. (Biological Survey collection^ (orig. no. 817). 

Range. — Southeastern Washington and nortliern Oregon; north to 
southern Adams County, Wash. ; east at least to the Idaho- Washing- 
ton boundary; south to Heppner, Oreg. ; west to Willows, Oreg. 
(fig. 3). Zonal range: Upper Sonoran. 

External characters. — Size medium; tail short; dorsal area dis- 
tinctly spotted, general tone grayish. 

Granial characters. — Skull similar to that of G. idahoensis but 
averaging smaller, and relatively narrower ; interorbital constriction 
narrower; postorbital processes narrower at base and very slender 
throughout ; ascending arms of premaxillae narrower than the nasals 
(about equal in idahoensis) ; auditory meatus much shorter. Com- 



70 



NORTH AMERICAN FAUNA 



[No. 56 



pared with G. townsendii townsendii: Skull averaging larger, with 
relatively narrower brain case and interorbital region. 

Color. — Winter pelage (March) : General tone of upper parts pale 
smoke gray, faintly washed (except on head) with pinkish buff, the 
entire back flecked with squarish, grayish white spots averaging 
about 3 or 4 mm in breadth; patch on nose and front of face 
cinnamon; eyes surrounded with a narrow wliitish ring; sides of 
body very faintly washed with pale buff; feet whitish, tinged with 
pinkish buff, thighs pinkish cimiamon; tail above, grayish mixed 
with fuscous, with a subterminal band of fuscous black, tipped with 
buffy white; tail beneath, pinkish cimiamon sometimes mixed with 
fuscous and edged with buffy white; under parts grayish white, 
washed with pinkish buff, the bases of the hairs fuscous. Summer 
pelage (August) : Upper parts more brownish or fuscous than in 

winter, due appar- 
ently to wearing 
away of the whitish 
or buffy tips on the 
hairs and exposure 
of the subterminal 
brownish areas. 

Molt. — Numerous 
specimens taken in 
May and June are in 
badly worn pelage, 
but no clear indica- 
tions of the molt 
have been found in 
the series examined; 
probably, as in the 
case of other species, 
the pelage is renewed 
during the early part 
of sunnner. 

Measuretnents. — Average of 15 adults from Wallula, Pasco, and Toueliet, 
Wash. : Total length, 229.2 (212-245) ; tail vertebrae, 50 (40-65) ; hind foot, 
35.3 (34-38). Skull: Average of 16 adults (5 males, 11 females) from same 
localities: Greatest length, 38.5 (36.8-41.4); palatilar length, 18.3 (17-20); 
zygomatic breadth, 24.8 (23.3-26.2) ; cranial breadth 17.2 (16.3-18.3) ; inter- 
orbital breadth, 7.4 (6.6-8.2) ; postorbital constriction, 9.2 (8-10.3) ; length of 
nasals, 13.8 (13-15.6) ; maxillary tooth row, 7.8 (7.3-8.3). Oregon specimens 
average larger than those from the type region ; average of 10 adult males from 
Pendleton and Willows: Greatest length, 39.4 (38.5-41.8) ; zygomatic breadth, 26 
(24.8-27.5) ; cranial breadth, 18.1 (16.8-18.7). 

Weight. — Shaw (19251, p. 764) gives the weight of a male at time of enter- 
ing hibernation as 280 g ; on av/akening at the end of a period of 56 days the 
same animal weighed 221 g. 

Remarks. — This ground squirrel has been known for nearly half a 
century under the name Citdlus townsendii, but as shown on page 62, 
that name is applicable to another species. Therefore it has become 
necessary to provide a name for the species under consideration. 

The Washington ground squirrel is easily recognized among the 
American forms by its relatively short tail and conspicuous dorsal 
spotting. It is spotted much as in certain forms of G. spilosoma, 
but the latter have longer tails, harsher pelage, and differ widely in 




Figure 3. — Distribution of Citellus brunneus and sub- 
species of C. icashinytoni: 1, C. w. loringi ; 2, G. iv. 
ivashingtoni; 3, C. brunneus. 



1938] REVISION OF THE GROUND SQUIRRELS 71 

skull characters. The present form resembles G. guttatus of south- 
ern Russia rather closely in general appearance, but the available 
material does not permit of detailed comparison. There is, of course, 
no chance of close relationship between the two. 

The nearest relative of C. washingtoni is C. hrunneus of west- 
central Idaho, originally described by the writer as a subspecies of 
townsendii\^ = washing toni]^ but now believed to be a distinct species. 

The range of this species is separated from that of G. townsendii 
townsendiihj the Columbia River; in northern Oregon, luashingtoni 
occupies an area west of the Blue Mountains and east of John Day 
River, while G. tovnsendii canus occupies most of the semidesert 
regions of the State to the southward. The ranges of washingtoni 
and townsendii apparently do not overlap. 

Specimens examined. — Total number, 112, as follows : 

Oregon: Cold Springs (Umatilla County), 1; Heppner, 9; Pendleton, 17; Pilot 
Rock (Umatilla County), 3; Umatilla, 1; Vinson (Umatilla County), 2; 
Willows (Gilliam County), 6; Willows Junction, 1. 

Washington: Almota (Whitman County), 4; Columbia River, 1;" Riparia 
(Whitman County), 1; Othello (Adams County), 1;" Pasco, 19; Pataha 
(Columbia County), S;" Touchet, 27; Wallula, 8;" Wawawai, 2." 

CITELLUS WASHINGTONI LORINGI, suESp. nov. 

Loeing's Ground Squirrel 

Type. — Collected at Douglas, Wash., August 1, 1897, by J. Alden 
Loring; male adult, skin and skull; no. 89805, U. S. Natl. Mus. (Bio- 
logical Survey collection) (orig. no. 4547). 

Range. — Plains of east-central Washington, south and east of the 
Columbia River, including most of Douglas, Grant, Lincoln, and 
Adams Counties; east to Spokane County (fig. 3). Zonal range: 
Upper Sonoran. 

Gharacters. — Similar in color and cranial characters to G. w. wash- 
ingtoni but smaller. 

Measurements. — Average of 10 adult males from type region (Douglas, 
Waterville, Baird, Farmer, Coulee Citv) : Total length, 203 (185-224) ; tail 
vertebrae, 39.6 (32-48); hind foot, 30.8 (30-33). Skull: Average of 10 
adult males from same localities: Greatest length, 36.4 (35-38); palatilar 
length, 17.5 (17-18) ; zygomatic breadth, 23.4 (22.6-24.5) ; cranial breadth, 
17.2 (16.4-18) ; interorbital breadth, 7 (6.4-7.7) ; postorbital constriction, 9.7 
(9-11); length of nasals, 13.4 (12.,S-14.7) ; maxillary tooth row, 7.7 (7.5-8). 

Remarks. — This race, occupying the high plains at the northern 
limit of the range of the species, is characterized mainly by being 
smaller than the typical form. Specimens from Sprague, Wash., 
are intermediate between Joringl and the typical race. 

Specimens examined. — Total number, 20, as follows: 

Washington: Baird (Douglas County), 3; Cheney, 1; Coulee (Grant County), 
2; Douglas, 2; Farmer (Douglas County), 2; Harrington, 1; Mansfield, 
1; Moses Coulee (Douglas County), 1; Sprague, 5; Waterville, 1; Wil- 
bur, 1. 



>"Type, Acad. Nat. Sci. Philadelphia. 
*^ TIniv. Michigan Mus. Zool. 
" Four in Univ. Michigan Mus. Zool. 
"Field Mus. Nat. Hist. 



72 NORTH AMERICAN FAUNA [No. 56 

CITELLUS BRUNNEUS Howell 

Idaho Spotted Ground Squiekel 

(Pis. 23, D; 28, D) 

Citellus townsendii drunneus Howell, Biol. Soc. Wash. Proc. 41: 211, Dec 
18, 1928. 

Type. — Collected at New Meadows, Adams County, Idaho, July 11, 
1913, by L. E. Wyman; female adult, skin and skull, no. 201963, 
U. S. Natl. Mus. (Biological Survey collection) (orig. no. 178). 

Range. — West central Idaho, in Washington, Adams, and Valley 
Counties ; limits of range unknown (fig. 3) . Zonal range: Transition 
and Upper Sonoran. 

External characters. — Similar to C. washingtoni wasliingtoni but 
color of upper parts more brownish (less grayish) and the dorsal 
spots smaller; cinnamon patch on face darker and more extensive; 
tail longer and darker (more blackish) ; ears much larger, raised 
conspicuously above the crown. Compared with G. idahoensis: 
Upper parts more brownish and distinctly spotted; tail with more 
black; ears larger. 

Cranial characters. — Skull similar to that of washingtoni but aver- 
aging larger and relatively broader, especially the rostrum and the 
postorbital region; nasals longer; last upper molar with posterior 
Joph practically obsolete. Compared with idahoensis: Skull averag- 
ing slightly smaller but broader across postorbital region; nasals 
larger (both longer and broader) ; audital bullae smaller; external 
meatus shorter. 

Color. — Summer pelage (July) : General tone of upper parts smoke 
gray, more or less heavily washed on the back with pinkish cinnamon 
or sayal brown, and moderately sprinkled with small, quadrangular 
spots of grayish white; front of face with a rather extensive patch 
of sayal brown ; eyes surrounded with a broad ring of creamy white ; 
sides of neck and body faintly washed with pinkish buff ; feet pinkish 
buff ; thighs pale russet ; tail above, dark sayal brown at base, shaded 
on distal portion with fuscous black and all sprinkled with grayish 
Avhite ; tail beneath, cinnamon, shaded with grayish white and fuscous, 
and edged with cinnamon buff; under parts grayish white, shaded 
with pinkish buff. 

Measurements. — Average of 13 adults from type region (New Meadows, Mid- 
vale, Van Wyck, Goodrich, and Weiser) : Total length, 232.5 (214-252) ; tail 
vertebrae, 56.7 (51-61) ; hind foot, 34.2 (33-37) ; ear from notch, 10.5 (&-12). 
Skull: Average of 5 adult males from Weiser and Midvale, Idaho : Greatest 
length, 40.1 (38.7^0.8) ; zygomatic breadth, 25.5 (24.9-26.1) ; palatilar length, 
18.6 (18-19) ; cranial breadth, 18.4 (18.1-18.5) ; interorbital breadth, 8.3 (7.5- 
9.2) ; postorbital constriction, 10.9 (10.4-11.6) ; length of nasals, 14.8 (13.7-16.1) ; 
maxillary tooth row, 8.4 (8.1-8.8). Average of 3 adult females (including type) : 
Greatest length, 37.3 (36.4-38.2) ; palatilar length, 17.3 (17-18) ; zygomatic 
breadth, 23.8 (23.4-24.1) ; cranial breadth, 17.8 (17.2-18.6) ; interorbital breadth, 
7.8 (7.6-8.1) ; postorbital constriction, 10.4 (9.5-11.2) ; length of nasals, 13.4 
(33.1-13.8) ; maxillary tooth row, 7.9 (7.5-8.2). 

Remarks. — This well-marked species apparently has a rather re- 
stricted distribution in west-central Idaho, where it meets or slightly 
overlaps the range of C. townsendii mollis (at Weiser). It is readily 
distinguished from both idahoensis and mollis by its distinct dorsal 
spotting and its large ears. 



1938] REVISION OF THE GROUND SQUIRRELS 73 

Originally described by the writer as a subspecies of C. townsendii 
\_— leashing toni], it appears on more detailed comparison to be a dis- 
tinct species, distinguished from washingtoni by larger ears, longer 
and darker tail, smaller dorsal spots, and by the skull characters 
pointed out above. 

Specimens examined. — Total number, 14, as follows: 

Idaho: Goodrich (Adams County), 1; Midvale (Washington County), 3; New 
Meadows (Adams County), 2; Van Wyck (Valley County), 2; Weiser, 6. 

CITELLUS RICHARDSONn GROUP 

CITELLUS RICHARDSONII (Sabine) 
[Synonymy under subspecies] 

SpecifiG characters. — ^Size medium to large ; hind foot 39.5-48 mm ; 
tail 65-100 ; skull length 42-48.6. Dorsal outline of skull convex, the 
highest point being between the postorbital processes; brain case 
harrow and deep, much constricted anteriorly; postorbital processes 
long, slender, and decurved; interorbital constriction pronounced; 
zygomata heavy and broad, widely expanded posteriorly, narrowing 
anteriorly ; rostrum moderately narrow ; nasals ending nearly on the 
j)lane of the posterior ends of premaxillae, or shorter; antorbital 
canal suborbicular ; upper tooth rows slightly convergent poste- 
riorly ; auditory bullae rather small, low and broad ; auditory meatus 
slightly produced; upper incisors moderately slender and nearly 
straight. 

Coloration of upper parts drab or smoke gray, more or less shaded 
with fuscous and dappled with cinnamon buff; under parts pale buff 
or cinnamon buff; under side of tail clay color, cinnamon buff, or 
sayal brown. 

CITELLUS RICHARDSONII RICHARDSONII (Sabine) 

Richardson's Gbound Squirrel 

(Pis. 2; 25, F; 30, F) 

Arctomys richardsonii Sabine, Trans. Linn. Soc. London 13 : 589, 1822. 
Arctomys (Spermophilus) richardsonii Richardson, Fauna Boreali-Amer., p. 

164, 1829. 
Spermophilus richardsonii F. Cuvier, Sup. Sl I'hist. natur. Buff on 1 : 323, 1831. 
[Citellus] richardsoni Trouessart, Cat. Mamm., Sup., p. 338, 1904. 

Type (lectotype).^^ — Collected at Carlton House, Saskatchewan, by 
Sir John Richardson; no. 63a, British Museum. 

Range. — Plains of southern Alberta, southern Saskatchewan, south- 
western Manitoba, northern and central Montana, North Dakota 
(except southwestern part), and northeastern South Dakota; north 
to the North Saskatchewan Eiver; east to the Red River Valley, 
N. Dak., Big Stone Lake, S. Dak,, and the western edge of Minne- 
sota; south to east-central South Dakota (Jerauld County), and 
southwestern Montana (Gallatin and Park Counties) ; west to the 
foothills of the Rocky Mountains in Alberta and Montana (fig. 4). 
Zonal range: Transition. 

External characters. — Size large; hind foot, 43-47 mm; tail about 
one-fourth the total length; ears broad and low (2-4 mm above 



"Selected by O. Thomas (1927, p. 545). 



74 



NORTH AMERICAN FAUNA 



[No. 56 



crown) ; coloration above nearly uniform buffy or drab, with slight 
"dappling" ; under parts deep buff in summer pelage. 

Graniaf^ characters. — As given under specific characters ; compared 
with* 0. r. elegans^ the skull is larger, with longer and relatively 
narrower rostrum. 

Color. — Fresh summer pelage (July) : General tone of upper parts 
pinkish buff or cinnamon buff, shaded with fuscous (caused by ex- 
posure of the subterminal bases of the hairs), the posterior part of 
back showing a distincthf "dappled" effect; nose with a large patch 
of cinnamon; eye ring light buff; sides of head and neck and front 
of fore le^s cinnamon buff or clay color; sides of body and under 
parts pinkish buff or cinnamon buff ; hind feet pinkish buff ; tail above, 
fuscous black, mixed with pinkish buff and broadly edged with the 
same; tail beneath, cinnamon buff or clay color, edged with pinkish 
buff. In worn pelage much of the buffy tone of the upper parts 
is lacking, the general effect being near smoke gray. 

Molt. — Apparently the molt may occur at any time in the spring 
or summer. Specimens taken in April at Choteau, Mont., are in a 

much -worn pelage 
and one— a breeding 
female — shows a 
patch of new hair 
extending along the 
middle of the back 
from the head nearly 
to the rump. An- 
other adult female 
from Blackfoot, 
Mont., June 12, is in 
similar condition of 
molt. An adult fe- 
male from Wingard, 
Saskatchewan, July 
15, is much worn on 
the anterior half of 
the body and shows 
new pelage covering the posterior half to the middle of the back. 

Measurements. — Average of 16 adults (7 males, 9 females) from type 
locality: Total length, 2S5.4 (277-306) ; tail vertebrae, 73.8 (65-83) ; hind foot, 
44.9 (43-47). Skull: Average of 7 adult males from type locality: Greatest 
length, 47.7 (47.3^8) ; palatilar length, 23.7 (23-25) ; zygomatic breadth, 31.9 
(30.5-33.5) ; cranial breadth, 20.2 (19.9-20.8) ; interorbital breadth, 9.9 (9.5- 
10.6) ; postorbital constriction, 11.4 (10.8-11.9) : length of nasals, 17.4 (17-18) ; 
maxillary tooth rovs^, 10.4 (10.2-10.7). Average of 8 adult females from type 
locality: Greatest length, 46.5 (45.1-48.4); palatilar length, 23.1 (22.5-24): 
zygomatic breadth. 30.4 (29.5-31.2) ; cranial breadth, 19.6 (19-20.9) ; interorbital 
breadth, 9.5 (8.8-10) ; postorbital constriction, 11.1 (10.8-11.5) ; length of nasals, 
16.9 (16-18.1); maxillary tooth row, 10.4 (10-10.9). Average of 6 adults (3 
males, 3 females) from Choteau County, Mont. : Greatest length, 48.1 (46.5- 
49.9) ; palatilar length, 24.4 (23.2-26) ; zygomatic breadth, 32.5 (31.5-33.1) ; 
cranial breadth, 20 (19.2-20.8) ; interorbital breadth, 9.8 (8.7-11.7) ; postorbital 
constriction, 10.6 (9.8-11.2) ; length of nasals, 17.8 (17.2-18.7) ; maxillary tooth 
row, 10.5 (10.1-11). 

Weight. — In spring, 11 to 13 ounces ; in fall 16 to 11 V2 ounces (Bailey, 1926, 
p. 58). 

Remarhs. — Richardson's ground squirrel has an extensive range in 
the Great Plains region of southern Canada, Montana, and the Da- 




FiGDKE 4. — Distribution of tlie subspecies of Citellus rich- 
ardsonii: 1, C r. richardsonii ; 2, C. r. elegansj 3, C. r. 
nevadensis. 



1938] REVISION OF THE GROUND SQUIRRELS 75 

kotas. The species apparently has extended its range southward in 
South Dakota in recent years and is now found regularly along the 
northern border of Jerauld, Sanborn, Miner, and Lake Counties, with 
several outlying records of occurrence in Hanson County in 1932. 

It is reported also to have extended its range into western Minne- 
sota; Surber (1932, p. 58) states that colonies have recently been es- 
tablished in Norman County and near Enok, Kittson County; Louis 
EjQowles reports that these ground squirrels invaded the western 
borders of the counties of Traverse, Big Stone, and Lac qui Parle in 
1934. 

In Gallatin County, Mont., richardsonii grades into the smaller and 
darker race, elegans^ which occupies most of the southwestern corner 
of the State. 

Specimens examined. — Total number, 349, as follows : 

Alberta: Calgary, 8;" Red Deer, 7. 

Manitoba: Brandon (IS miles east) , 1 ;" Carberry, 56 ; Petrel (Norfolk District) , 1. 

Montana: Blackfoot (Glacier County), 11; Blackfoot Agency (Glacier County), 
6; Big Belt Mountains (Meagher County, south of Fort Logan), 3; Big 
Timber Creek, Crazy Mountains ( Sweetgrass County ) , 4 ; Birch Creek 
(Teton County), 4; Bozeman, 10; Bruno (Meagher County), 3;'^ Buffalo 
(Fergus County), 1; Chief Mountain (Glacier County), 1; Choteau, 11; 
Dry Creek (Gallatin County), 2; East Gallatin River, 4; Flat Willow Creek, 
3.24 Yovt Ellis (near Bozeman), 1; Frenchmans River (at international 
boundary), 4; Glasgow, 5; Great Falls, 1; Grafton (Judith Basin County), 
1; Johnson Lake (Roosevelt County), 2; Lewistown, 3; Livingston, 5; 
Manhattan (Gallatin County), 2; Martinsdale (10 miles east, Wheatland 
County), 2; Milk River (at mouth, at 49°, and at Two Forks), 5; Moccasin 
Mountains (Fergus County), 3; Philbrook (Judith Basin County), 1; Ring- 
ling (10 miles south, Meagher County), 3;'^ Roy (Fergus County), 1; St. 
Mary, Glacier National Park, 11;=^ Sedan (Gallatin County), 2;'^ Shelby 
Junction, 5; Summit (near Ringling, Meagher County), 1; Sun River Cross- 
ing (Cascade County), 1; Teton (Choteau County), 1; Three Buttes (on 
International boundary, Hill County), 15; Toston (Broadwater County), 
1;-^ Townsend (Broadwater County), 3;" Tyler (Fergus County), 1; Ubet 
(Wheatland County), 5; West Gallatin River (Lower Basin), 1; West 
Gallatin and Spanish Canyons (Gallatin County), 3.^ 

North Dakota: Ashley, 1; Bismarck, 11; Bottineau, 8; Bowdon, 2;" Buford 
(Williams County), 6; Crosby, 1; Devils Lake, 15; Drayton, 6; Ellendale, 
1 ; Grafton, G ; Hankinson, 1 ; Kenmare, 1 ; LaMoure, 6 ; Larimore, 2 ; Lisbon, 
1; Lostwood (Mountrail County), 1; Pembina, 2; Rush Lake (Cavalier 
County), 2; St. John (Rolette County), 2; Starkweather (Ramsey County), 
1; Stump Lake (Nelson County), 1 ;"" Towner, 1; Turtle Creek (near Wash- 
burn), 1; Turtle Mountains, 2; Washburn, 4. 

Saskatchewan : Carleton, 5 ; Indian Head, 3 ; Livelong, 1 ; *" Moosejaw, 3 ; Win- 
gard, 20. 

South Dakota : Aberdeen, 2 ; Frederick, 4 ; Wahvorth County. 1. 



22 Five in collection of C. B. Garrvtt. 

23 Kansas Univ. Mus. 

2< Montana Slate College. 
25 Univ. Michigan Mus. Zool. 
2« William T. Shaw coll. 
27 Carnegie Mus. 



76 NORTH AMERICAN FAUNA [No. 56 

CITELLUS RICHARDSONII ELEGANS (Kennicott) 

Wyoming Ground Squireel 

(Pis. 25, E; 30, E) 

Spermophilus elegans Kennicott, Acad. Nat. Sci. Phila. Proc. .186.3: 158. 
ISpermophilus ricliardsoni] var. elegans Allen, Boston Soc. Nat. Hist. Proc. 

16: 292, 1874. 
ISpermophilus richardsoni] var. townsendi Allen, Monog. North Amer. Rodentia, 

p. 850, 859, 1877 (part). 
[Citellus] elegans Trouessart, Cat. Mamm., Sup., p. 339, 1904. 

Cotypes. — Collected at Fort Bridger, Wyo., April and May 1858, 
by C. Drexler; female, skin and fragments of skull, no. |||^ ; male, 
skin and part of skull inside, no. 3480; skin no. 5955 ; skin (in alcohol) 
and skull, no. ffff ; alcoholics, nos. 5951, 5952, 5953, 5954; also, a few 
other fragments in U. S. Natl. Mus. (Lyon and Osgood, 1909, p. 165). 

Range. — Southwestern Montana, southeastern Idaho, southern 
Wyoming, and northwestern Colorado; north to Madison and 
Beaverhead Counties, Mont., and northwestern Converse County, 
Wyo.; east to extreme southeastern Wyoming; south to Leadville, 
Colo.; west to Custer County (Big Lost River Valley), Idaho (fig. 
4) . Zonal range : Mainly Transition. 

External characters. — Similar to C. r. richardsonii but smaller, 
with shorter hind feet; coloration of upper parts in summer less 
buffy (more grayish or brownish) ; under parts and sides of head 
and shoulders paler in summer pelage; tail usually darker and more 
blackish beneath, but with paler edgings. 

Cranial characters. — Skull similar to that of richardsonii but 
smaller; rostrum shorter and relatively broader; nasals shorter. 

Color. — General tone of upper parts light drab, more or less 
flecked with light pinkish buff, some specimens showing a decided 
pinkish or brownish tone on the middle of the back, the head and 
shoulders frequently more or less washed with smoke gray; nose 
cinnamon buff, clay color, or pinkish cinnamon; eye ring white or 
buffy white ; feet pinkish buff or ivory yellow ; tail above, similar on 
basal portion to the back, the terminal half broadly bordered with 
fuscous black and edged with pale buff ; tail beneath, cinnamon buff 
or pale cinnamon, bordered on terminal portion with fuscous black ; 
lower sides and under parts cartridge buff. 

Measurements. — Average of 10 adults from Fort Bridger and New Fork of 
Green River, Wyo.: Total length, 262.3 (253-272) ; tail vertebrae, 72.9 (66-78) ; 
hind foot, 40.7 (39.5-43). Skull: Average of 12 adults (9 males, 12 females) 
from vicinity of type locality (Fort Bridger, Evanston. Cumberland, Lone 
Tree) : Greatest length, 43.1 (42^4.8) ; palatilar length, 20.9 (20-22.2) ; zvgo- 
matic breadth, 28.8 (27.5-30) ; cranial breadth, 19.7 (18.7-20.5) ; interorbital 
breadth, 9.3 (8.5-10) ; postorbital constriction, 11.3 (10.5-11.7) ; length of nasals, 
15.3 (14.7-16.1); maxillary tooth row, 9.4 (9-9.7). 

Remarks. — The Wyoming ground squirrel was originally de- 
scribed by Kennicott as a distinct species. Allen (18YT, p. 850), cor- 
rectly associated it with C. richardso^iii as a variety, but misapplied 
Bachman's name townsendii to it. It continued to be known by that 
name until 1891, when Merriam revived Kennicott's name for it and 
suggested that it might prove to be a subspecies of richardsonii. The 
material now available shows this to be the case, intergradation be- 
tween the two forms occurring in Gallatin County, Mont. Speci- 
mens of elegans in winter pelage are scarcely distinguishable from 



1938] REVISION OF THE GROUND SQUIRRELS 77 

comparable specimens of C . r. ridiardsonii^ except by their smaller 
size, but in summer pelage elegans is decidedly grayer and less buffy. 
Specimens examined. — Total number, 229, as follows : 

Colorado: Canadian Creek (North Park), 3; Coulter (Grand County), 6; Elk- 
horn (Larimer County, near Log Cabin), 2; Estes Park, 1;^ Fairplay, 2; 
Fish Creek (Routt County), 2; Fort Collins (Buckhorn Ranger Station), 
6; Garo (Park County), 1; Leadville (10 miles south), 2;^ Mount Whitely 
(Grand County), 1; Rabbit Ear Mountains (Jackson County), 1; Sopris 
National Forest (west of Thomasville), 1; Steamboat Springs (15 miles 
west), 3; Wolcott (Eagle County), 1.=° 

Idaho: Birch Creek (Clark County), 5; Dickey (Custer County), 10; Forney, 
1: Henry Lake, 1; Lemhi Mountains (west of Junction), 1; Montview, 1; 
Patterson (Bingham County), 3; Pleasant Valley (Clark County), 1. 

Montana: Alder, 1; Big Hole Bench (west of Wisdom, Beaverhead County), 1; 
Dillon, 14 ; ^ Ennis Lake, 2 ; Harrison, 3 ; Lakeview, 2 ; Lower Bedrock Lake 
(Beaverhead County), 1;'* Pony (Madison County), 1; Red Bluff (Madi- 
son County), 1; Virginia City, 5; Wisdom (9 miles north, Beaverhead 
County), 3." 

Wyoming: Altvan (Laramie County), 1; Bear Creek (Albany County, near 
Eagle Peak), 1; Big Piney (Sublette County), 1; Big Sandy (Sublette 
County), 2; Bitter Creek, 5;'^ Bridger Pass (Sweetwater County), 7; 
Bridger Peak, Sierra Madre Mountains, 1 ; Cheyenne, 8 ; Cokeville, 6 ; Cum- 
berland, 9; Evanston, 4: Fort Bridger (Uinta County), 18; Fort Russell 
(Laramie County), 6; Fort Saunders (=Laramie), 1; Fort Steele (Carbon 
(IJounty), 2; Fossil (Lincoln County), 8; Green River (City), 3; Green River 
(at mouth of New Fork), 5 ; Islay (Laramie County), 2 ; Kemmerer, 1 ; Kin- 
ney Ranch (Bitter Creek. Sweetwater County), 3; Laramie, 1; Laramie 
River, 1 ; Laramie Mountains, 3 ; Little Medicine Bow River (Carbon 
County), 1; Little Piney Creek (Sublette County), 1; Lonetree (Uinta 
County), 9; Medicine Bow ^Mountains, 2; Mountainview (Uinta County), 
2; New Fork, Green River (Lander Road), 4; Opal (Lincoln County), 1; 
Pinedale, 2; Poison Spider Creek (Natrona County), 1; Pole Mountain (15 
miles southeast of Laramie), 2; Rawlins, 2; Riverside (Carbon County), 
1; Sage (Lincoln County), 4; South Pass City (Fremont County), 1; Supe- 
rior, 4; Woods P. O. (Medicine Bow Mountains, Albany County), 4. 

CITELLUS RICHARD SONII NEVADENSIS Howell 

Ne:\-ada Ground Squirrel 

Citellus elegans nevadensis Howell, Biol. Soc. Wash. Proc. 41: 211, Dec. 18, 1928. 

Type. — Collected at Paradise, Plumboldt County, Nev., March 3, 
1908, by Stanley E. Piper; female adult, skin and skull; no. 156788, 
U. S. Natl. Mus. (Biological Survey collection) (orig. no. 112). 

Range. — Northern Nevada, extreme southeastern Oregon, and ex- 
treme southwestern Idaho; from Paradise Valley, east to Metropolis 
and south to Kuby Valley, Nev. (fig. 4). Zonal range: Upper 
Sonoran and Transition. 

External characters. — Similar to C. r. elegans but larger, with 
longer tail and hind feet; upper parts averaging more grayish (less 
brownish), especially on head and shoulders; under parts darker 
buff. Compared with G. heldingi oregonus: Size larger; upper parts 
paler and more buffy (less reddish) ; under parts more buffy; tail 
paler and less reddish beneath. 

Cranial characters. — Skull similar to that of elegans but averaging 
decidedly larger; postorbital constriction averaging less. Compared 



28 Univ. of Michigan Mus. Zool. 

™ State Hist. Soc. of Colorado (Denver). 

*> Eight in Kansas Univ. Mus. Nat. Hist. 

»i Montana State College. 

aa Field Mus. Nat. Hist. 



78 NORTH AMERICAN FAUNA tNo. 56 

with G. r. richardsonii : Skull averaging slightly larger, with broader 
rostrum, nasals, and audital bullae ; tooth row shorter. 

Color. — (Type, March 3) : Patch on front of face mikado brown 
(varying in other specimens to wood brown or pinkish cinnamon) ; 
head and shoulders smoke gray, shaded with fuscous ; eye ring broad, 
buffy white ; back smoke gray shaded with cinnamon buff, the median 
area darkened with fuscous; feet pinkish buff; tail above, mixed 
fuscous and pinkish buff, edged with pale buff; tail beneath, sayal 
brown, tipped with fuscous; lower sides and under parts cinnamon 
buff, shading to pale buff on chin and throat. 

Measurements. — Type (? ad., from dry skin) : Total length, 337; tail verte- 
brae, 100; hind foot, 47. Average of 9 adults from Ruby Valley, Skelton, and 
McDermitt, Nev. : Total length, 291.1 (270-307) ; tail vertebrae, 88.1 (7&-100) ; 
hind foot, 46.1 (42--48). BUull: Average of 6 adults (3 males, 3 females) from 
Paradise, Metropolis, and McDermitt, Nev. : Greatest length, 47 (44.7-48.6) ; 
palatilar length, 23 (22-24) ; zygomatic breadth, 31.3 (29.9-32.4) ; cranial 
breadth, 20.9 (19.6-21.7) ; interorbital breadth, 10 (9.2-11.6) ; postorbital con- 
striction, 10.6 (9.7-11.5) ; length of nasals, 17.7 (17-18.6) ; maxillary tooth row, 
9.6 (9.3-10.3). 

Remarks. — The Nevada ground squirrel is fully as large as typical 
richardsonii but is grayer and less buffy and the tail is darker and 
more tawny beneath. It undoubtedly intergrades with elegans, but 
its range as at present known appears to be isolated from the range 
of that race. It overlaps the range of oregonus., occurring often in 
the same localities, but the two are quite distinct. 

Specimens examined. — Total number, 33, as follows : 

Idaho: Riddle (Owyhee County), l.** 

Nevada: Elko, 9; Metropolis, 5; Mountain City (Elko County), 2; Paradise 

(Humboldt County) , 2 ; Ruby Valley, 5 ; Skelton (30 miles south of Elko) , 2. 
Oregon: Malheur County (near McDermitt, Nev.), 4; Rattlesnake Creek (at 

head, Malheur County), 3. 

CITELLUS ARMATUS (Kennicott) 

Uinta Gkound Squirrel 

(Pis. 23, F; 28, F) 

Spermophiliis armatus Kennicott, Acad. Nat. Sci. Phila. Proc. 1863: 158. 
[Cifellus] armatus Trouessart, Cat. Mamm., Sup., p. 339, 1904. 

Cotypes. — Collected in the foothills of the Uinta Mountains, near 
Fort Bridger, Wyo., April to June 1858, by C. Drexler; nos. 3464 
and 3476, skins [fragmentary] with skulls inside; nos. 4794, 4808, 
4809, fragmentary skulls ; nos. 5958, 5959, 5960, alcoholics (Lyon and 
Osgood, 1909, p. 163). 

Range. — Mountains and foothills of western Wyoming, extreme 
southwestern Montana, southeastern Idaho, and northern and central 
Utah; north to Beaverhead, Madison, Gallatin, and Park Counties, 
Mont. ; east to the eastern foothills of the Shoshone and Wind River 
Mountains, Wyo. ; south to Fish Lake Plateau, Utah ; west to Dono- 
van, Mont., Mount Harrison, Cassia County, Idaho, and the Raft 
River Mountains, Utah (fig. 5). Zonal range: Canadian and Transi- 
tion. 

Ea;ternal characters. — Similar to G. richardsonii elegans^ but 
slightly larger, with longer hind feet, tail of nearly the same length ; 
ears larger; upper parts decidedly darker; tail more grayish (less 

«Mus. Vert. Zool. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



79 



buffy) beneath. Compared with C. teldingi oregonus: Closely sim- 
ilar in size and coloration, but dorsal region slightly darker, the 
rmnp and thighs more tawny (less grayish) ; tail grayish rather than 
reddish beneath, the bordering hairs more buffy (less grayish). 

Cranial characters. — Skull similar to that of G. r. richardsonU but 
averaging slightly longer, and narrower across zygomata; cranium, 
interorbital region, and rostrum broader, but postorbital constriction 
less ; audital bullae 
broader, with longer 
meatus; nasals 
slightly longer ; max- 
illary tooth row 
shorter. Compared 
with elegans: Decid- 
edly larger, with 
broader rostrum and 
interorbital region, 
and longer and 
broader nasals. Com- 
pared with C. r. ne- 
vadensis: Similar in 
size, but averaging 
broader across zygo- 
mata; brain case 
and audital bullae 
broader. Compared 
with C. h. oregonus: 
Skull slightly larger ; 
nasals averaging 
broader at posterior 
end. 

Color. — ( Fresh 
pelage, June 12) : 
Head, front of face, 
and ears cinnamon, 
sprinkled on crown 
with gray; sides of 
face and neck pale 
smoke gray; eye ring cartridge buff; front legs cinnamon buff, shad- 
ing to pinkish buff on feet ; general tone of dorsal area sayal brown 
or cinnamon buff, the hairs tipped with pinkish buff, bases of the 
hairs fuscous; sides paler than back, mixed cartridge buff and fus- 
cous; thighs cinnamon; hind feet pinkish buff; tail, above and below, 
fuscous black, mixed with pale buff or buffy white, and edged with 
pinkish buff; under parts pinkish buff, shaded with buff'y white. 

Variation. — The intensity of the brownish color on the back varies 
considerably in different individuals; certain specimens, taken botli 
in midsummer and early spring, have the brownish tone much 
reduced, the hairs on the median dorsal area being pinkisli buff and 
the wliole back and sides washed with grayish white. Two specimens 
from Mountainview, Wyo., are uniform blackish brown all over. 

Molt. — The molting period is not clearly shown in the specimens 
examined, but probably in most individuals the molt occurs in June, 
or sometimes in May. A male from Hamsfork, Wyo., taken May 




Fiauui: 3. — Distribution of Citcllus annatus. 



go NORTH AMERICAN FAUNA [No. 56 

17, is in badly worn pelage, and shows a few small patches of new 
hair on the back. A nursing female from Spring Valley, Wyo., 
June 9, is likewise in a much worn pelage, with new hair covering 
the head and fore back. An adult male from Cooke, Mont., August 
11, shows worn hair on the anterior half of the body and a fuller, 
unworn pelage on the posterior half. 

Measurements. — ^Average of 12 adults from vicinity of tyue locality : Total 
length, 294 (280-303) ; tail vertebrae, 72.6 (63-81) ; Mnd foot, 43.9 (42^5.5) ; 
ear from notch, 11.2 (10-12). Skull: Average of 7 adult males from south- 
western Wyoming and Barclay, Utah: Greatest length, 47.8 (46.3-48.5) ; palat- 
ilar length, 23.2 (22.5-24) ; zygomatic breadth, 31 (30-31.8) ; cranial breadth, 
20.7 (19.2-21.5) ; interorbital breadth, 11 (10-11.3) ; postorbital constriction, 
10.9 (10.4-11.5) ; length of nasals, 17.8 (16.4-18.4) ; maxillary tooth row, 9.7 
(9.3-10). Average of 6 adult females from Fort Bridger and Spring Valley, 
Wyo.: Greatest length, 46.5 (45.6-48) ; palatilar length, 22.2 (22-23) ; zygomatic 
breadth, 30.2 (29.6-30.8) ; cranial breadth, 20.1 (19.8-20.4) ; interorbital breadth, 
10.2 (9.4-11.3) ; postorbital constriction, 11.3 (10-12.3) ; length of nasals, 17.2 
(16.&-17.9) ; maxillary tooth row, 9.8 (9.4-10.2). 

Remarks. — The Uinta ground squirrel is a distinct species, occupy- 
ing a rather limited area in the mountains from southern Montana 
south to Utah. It most nearly resembles oregonus, but the two are 
quite distinct and so far as known their ranges do not meet. The 
range of armatus meets and slightly overlaps that of elegans in parts 
of Montana and Wyoming, but in general this species occurs at higher 
altitudes and in more heavily wooded areas than does elegans. In 
some localities, however, as at Pinedale and Cokeville, Wyo., the two 
species occupy the same ground. 

Specimens examined. — Total number, 263, as follows: 

Idaho: American Falls, 1; ^ Arco (Butte County), 4; '^ Big Hole Mountains, 1; 
Blackfoot, 4; Blackfoot Mountains, 1; Clifton (Franklin County), 1; Elba 
(Cassia County), 1;^° Irwin (10 miles southeast, Bonneville County), 5; 
Malta (Cassia County), 1;^° Montpelier, 7; Mount Hai-rison (Cassia 
County), 1;^° Pahsimeroi River (head, Custer County), 1;^ Pocatello, 6; 
Shelley, 1; Swan Lake (Bannock Courity), 6; Teton Canyon, 1; Warm 
River (Fremont County), 1.^* 

Montana: Cooke (Park County), 11; Donovan (Beaverhead County), 1; Ennis 
Lake (Madison County), 2; Lakeview (Beaverhead County), 13; Spanish 
Creek (Gallatin County), 3; Virginia City (Eight-mile Spring), 4; Vir- 
ginia City (20 miles south), 3 ; Ward Peak (Tobacco Root Mountains, Mad- 
ison County), 6; West Boulder Creek (18 miles southeast of Livingston), 
3; West Gallatin River (West Fork, Gallatin County), 4; West Gallatin and 
Spanish Canyons (Gallatin County), 9.'" 

Utah: Barclay (Salt Lake County), 8; Blacksmiths Fork (Cache County), 1; 
Big Cottonwood Canyon (Salt Lake County), 1;" Bountiful, 1; Currant 
Creek (Wasatch County), 2; Fairview (Mammoth Ranger Station), 2; 
Farmington, 2; Fish Lake (Sevier County), 1; Fruitland, 3;*^ Hyde Park 
(Cache County), 1; Laketown (Rich County), 2: Lakota, Bear Lake, 1 ;^' 
Logan Canyon (Cache County), 1;'^ Mantua (Box Elder County), 1;^ Mount 
Pleasant, 1; Mount Timpanogas (Utah County), 2;^ Ogden"(Ogden Can- 
yon), 1; Park City, 17; Raft River Mountains, 1;'' Salt Lake City (Fort 
Douglas), 3; Sardine Canyon (Cache County), 2;'* Strawberry Valley (Du- 
chesne County), 9; Wellsville, 4. 

Wyoming: Afton (Lincoln County), 11; Border (Lincoln County), 5; Clarks 
Fork (opposite Crandall Creek, Park County), 1 ; Cokeville, 6; Daniel (Sub- 
lette County), 13; Evauston, 4; Fort Bridger, S; Gros Ventre Mountains 

** Donald R. Dickey collection. 

s^Mus. Vert. Zool. 

88 Montana State College, Bozeman. 

^ Acad. Nat. Sci. Philadelphia. 

^ Brigham Young Univ. 

s9 Utah State Agr. College. 

*i Carnegie Mus. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



81 



(Waterdog Lake), S;^ Hamsfork (Lincoln County), 2; Jackson, 5; Jakeys 
Creek (Fremont County), 1; Kemmerer, 7; Kendall (12 miles north, Sub- 
lette County), 2; Little Piney Creek (8,000 feet altitude, Sublette County), 
1; Merna (Sublette County), 1; Mountainview (Uinta County), 7; Opal 
(Lincoln County), 2; Pahaska (mouth of Grinnell Creek, Park County), 1; 
Spring Valley (Uinta County), 2; Stanley (8,000 feet altitude, Sublette 
County), 1; Valley (Park County), 5; Wind River Mountains (Upper Gros 
Ventre River, North Fork), 1; Wyoming Peak (10,900 feet altitude, Lincoln 
County), 1; Yellowstone National Park, 4. 

CITELLUS BELDINGI 

(Mereiam) 

[Synonymy under sub- 
species] 

Specific charac- 
ters. — Slightly small- 
er than G. r. richard- 
sonii; hind foot, 41- 
47 mm; tail, 55-76; 
skull length, 41.3- 
46.3. Skull similar 
to that of O. r. ele- 
gans but relatively 
longer, and narrower 
across zygomata, but 
broader interorbit- 
ally; zygomata slen- 
derer ; audital bullae 
smaller. Coloration 
of upper parts smoke 
gray, mixed with 
pinkish buff, the me- 
dian dorsal area 
more or less dark- 
ened ;with sayal 
brown or kaiser 
brown ; under side of 
tail hazel, upper side 
mixed with fuscous. 




Figure 6. — Distribution of the subspecies of Citellus bel- 
dingl: 1, C. 6. oregonus; 2, C. 6. beldingi. 



CITELLUS BELDINGI BELDINGI (Merriam) 

Bei.ding's Ground Squirrel 

(Pis. 3; 23, E; 28, E) 

Spermophilus heldingl Merriam, Ann. N. Y. Acad. Sci. 4 : 317, Dec. 28, 1888. 
[Citellus] beldingi Trouessart, Cat. Mamm., Sup., p. 339, 1904. 



Type.— Collected at Donner, Placer County, Calif., June 22, 1886, 
by Cliarles A. Allen; female adult, skin and skull, no. 186467, U. S. 
Natl. Mus. (formerly no. -VgVrj Merriam collection) (orig. no. 103). 

Range. — High mountain meadows in the central Sierra Nevada, 
from Nevada County (Independence Lake) south to the headwaters 
of Kings River, Fresno County, Calif, (fig. 6). Zonal range: Hud- 
sonian and Canadian, 6,500-11,800 feet altitude {jide Grinnell). 

External characters.— '^'wmX^x to G. arrnaius^ but upper parts 
darker and more reddish, the reddish color on the back usually in a 
well defined band; tail reddish instead of grayish beneath. 



*" Cleveland Mus. Nat. Hist. 
154070—38 6 



g2 NORTH AMERICAN FAUNA [No. 56 

Cranial characters. — Skull similar to that of G. richardsonii ele- 
gans (as defined under specific characters) ; smaller than that of 
armatus, with relatively broader interorbital region and less widely 
expanded zygomata. 

Color. — Front of face sayal brown, shading to hazel on top of head ; 
sides of face and head mixed fuscous and pinkish buflf ; eye rmg 
buffy white; nape mixed light buff and hazel; dorsal band (from 
nape to rump) hazel or kaiser brown (rarely sayal brown) ; sides of 
body mixed smoke gray and pinkish buff; feet pinkish buff; thighs 
cinnamon or sayal brown ; tail above mixed hazel and fuscous black ; 
tail beneath, hazel, bordered with tilleul buff and tipped with fus- 
cous black ; under parts dull whitish, more or less washed with pink- 
ish buff. 

Molt. — In the series examined there are no specimens that show 
clearly when these ground squirrels change their pelage. Grinnell 
and Dixon (1918, p. 659) consider that the species has but one molt 
annually, during July. 

Measurements. — Average of 12 adults (8 males, 4 females) from type local- 
ity: Total length, 279.6 (268-296) ; tail vertebrae, 68 (60-75) ; hind foot, 44.3 
(42— i7). Skull: Average of 10 adult males from type locality: Greatest length, 
45.2 (44-46.3) ; palatilar length, 21.8 (21-22.7) ; zygomatic breadth, 28.8 (27.8- 
29.8) ; cranial breadth, 19.5 (18.7-20.2) ; interorbital breadth, 11.2 (10.5-11.9) ; 
postorbital constriction, 11.7 (10.9-12.7) ; length of nasals, 16.9 (16.1-17.5) ; 
maxillary tooth row, 9.2 (9-9.4). Average of 10 adult females from tyiae 
locality: Greatest length, 44.7 (43.2-45.7); palatilar length, 21.8 (21-22.8); 
zygomatic breadth, 28.9 (28.2-29.6) ; cranial breadth, 19.5 (19.1-19.8) ; inter- 
orbital breadth, 11.1 (10.7-11.8) ; postorbital constriction, 11.7 (11.1-12.5) ; 
length of nasals, 16.1 (15.2-17.1) ; maxillary tooth row, 9.5 (9.2-10). 

Wei£^7il— Average of 10 adult males, 222 g (125.5-285) ; of 10 adult females, 
240 (172-^05) (Grinnell and Dixon, 1918, p. 660). 

Remarks. — Belding's ground squirrel, usually considered to be 
a distinct species, proves on examination of abundant material to be 
subspecifically related to C. ieldingi oregonus. It is rather strictly 
confined to the alpine meadows in the Sierra Nevada of California, 
and there appears to be a gap of about 25 miles between its range 
and that of oregonus. Notwithstanding this apparent hiatus be- 
tween their ranges, there is complete intergradation in characters 
between the two forms. 

Specimens examined. — Total number, 236, as follows: 

California: Alpine City, Bear Valley (Mariposa County), 1; American River 
(head of South Fork, near Silver Lake), 2; Bishop Creek (Inyo County), 
2; Donner (Placer County, including "Summit"), 97; Diamond Valley 
(Alpine County), 1;^^ Fredericksburg (Alpine County), 1;*^ Hope Valley 
(Alpine County), 4 ; *V Independence Lake (Nevada County), 13; Johnson 
Pass (8 miles south of Lake Tahoe), 1: Kaiser Pass (Fresno County), 1; *^ 
Little Pete Meadow (near head of Middle Fork of Kings River, Fresno 
County) 1;** Long Valley (Mono County), 2;*^ Mammoth (Mono County), 
3 ; McKinneys, Lake Tahoe, 7 ; Mono Lake, 4 ; *^ Mono Pass, 3 ; Mount 
Dana (Mono County), 3; Mount Conness (Tuolumne County), 1; Mount 
Tallac (Eldorado County), 2; Owens River (at head), 12; Pine City (Mono 
County, near Mammoth Pass), 1; Post Corral Meadows (Fresno County), 
2;** Sand Meadow (Fresno County), 1;** San Joaquin River (near Mam- 
moth Pass), 2; Sonora Pass (Alpine County), 2; Tahoe (Placer County), 
3; Terrace Meadow (Inyo County), 1;** Tioga Pass (Mono County), 1 ; *" 
Walker Lake (Mono County), 1 ; *^ Woodf ords (Alpine Coimty), 5;"^ Yosem- 
ite National Park, 52 (including Lake Tenaya, 7; head of Lyell Canyon, 



■^Mus. Vert. Zool. 

«Wm. T. Shaw Collection. 

" Cleveland Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 83 

6 ; ^ Merced Lake, 1 ; '' Mount Hoffman, 4 ; ^ Mt. Lyell, 1 ; Mount Unicorn, 
1; Porcupine Flat, 2; Tuolumne Meadows, 30);^" Zonoda Meadow (Inyo 
County), 1." 
Nevada: Near Bijou, Calif,, 3. 

CITELLUS BELDINGI OREGONUS (Mereiam) 

Oregon Ground Squirrel 

Spermophilus oregonus Merriam, Biol. Soc. Wash. Proc. 12: 69, Mar. 24, 1898. 
iCitellus} oregonus Trouessart, Cat Mamm., Sup., p. 339, 1904. 

Type. — Collected in Swan Lake Valley, Klamath Basin, Oreg., 
June 12, 1897, by Vernon Bailey; female adult, skin and skull, no. 
89177, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 
6005). 

Range. — Eastern Oregon, northeastern California, southwestern 
Idaho, and northern Nevada ; north to Heppner and Elgin, Oreg. ; 
east to Cassia County, Idaho, and Kuby Valley, Nev.; south to 
Plumas County, Calif., and Ruby Valley, Nev.; west to Klamath 
Lake, Oreg., and Goose Nest Mountain, Calif, (fig. 6). Zonal range: 
Upper Sonoran and Transition. 

External characters. — Similar to G. h. heldingi, but averaging 
slightly smaller; upper parts paler and more grayish, usually with- 
out a distinct reddish tone, and never with a well-defined band of 
reddish brown; similar to G. richardsonii elegans., but tail shorter 
and much darker (more reddish) beneath; coloration above usually 
darker and more reddish (less yellowish or buffy), with less indica- 
tion of mottling. Compared with G. armatus: Closely similar in 
size and coloration, but dorsal region paler, the rump and thighs 
more grayish (less tawny) ; tail reddish rather than grayish below, 
the bordering hairs more grayish (less buffy). 

Granial characters. — Skull similar to that of heldingi., but averag- 
ing slightly smaller and relatively narrower interorbitally. Com- 
pared with elegant: Skull relatively longer and narrower; zygomata 
weaker and more contracted anteriorly; auditory meatus shorter. 

Golor. — Upper parts smolie gray or pale smoke gray, more or less 
washed on the back with sayal brown, mikado brown, cinnamon, or 
light pinkish cinnamon; front of face with a patch of pinkish cin- 
namon or pinkish buff; under parts and sides washed with pinkish 
buff, the under fur on belly dusky neutral gray; feet pinkish buff; 
tail above, cinnamon or sayal brown mixed with smoke gray at base 
and heavily shaded with black on distal half; tail beneath, hazel, 
bordered with black and edged with pale tilleul buff. 

Molt. — Only a very few specimens in the large series examined 
show definite indications of molt; two adults (male and female) 
from Howard, Oreg., June 16 and 18, apparently are acquiring new 
pelage, the new hairs coming in irregularly over the whole back. A 
female from the Ruby Mountains, Nev., June 20, is in a worn gray- 
ish pelage, with a patch of fresh, reddish pelage coming in on the 
fore back. 

Measurements. — Average of 10 adult males from southwestern Oregon and 
northeastern California (Fort Klamath, Po Valley, Burns, Snsanville, Tule 
Lake) : Total length, 271.5 (254-300) ; tail vertebrae, G3.8 (55-76) ; hind foot, 



«Mus. Vert. Zool. 
"Cleveland Mus. Nat. Hist. 
**Ten In Mub. Vert. Zool. 



84 NORTH AMERICAN FAUNA [No. 56 

43 (41-45) ; average of 8 adult females from southern Oregon and northern 
California: 276; 67; 42.7. Skull: Average of 8 adult males from southwest- 
ern Oregon and northern California (Fort Klamath, Tule Lake, Susanville, 
Madeline Divide) : Greatest length, 45 (43.2^-46.2) ; palatilar length, 21.8 
(20.5-23) ; zygomatic breadth, 28.9 (28.1-30.1) ; cranial breadth, 20.2 (19.8- 
20.6) ; interorbital breadth, 10.1 (9.2-10.7) ; postorbital constriction, 11.7 
(10.7-12.3) ; length of nasals, 16.9 (16-18.2) ; maxillary- tooth row, 9.4 (9-10.1) ; 
average of 8 females from same region : Greatest length, 43.1 (41.3—44) ; 
palatilar length, 20.8 (19.8-21.5) ; zj'gomatic breadth, 27.8 (24.8-29.8) ; cranial 
breadth, 19 (18.2-19.5) ; interorbital breadth, 9.5 (9-10) ; postorbital constric- 
tion, 11.1 (10.4-12) ; length of nasals, 16.1 (15-17) ; maxillary tooth row, 
9 (8.6-9.3). 

Weight. — Two specimens weighed by Vernon Bailey registered 1 pound each ; 
one of these was recorded as very fat. Grinnell, Dixon, and Linsdale (1930, 
p. 483) record six individuals as weighing respectively, 212, 223, 230, 250, 260, 
and 260 g. Grinnell and Dixon (1918, p. 652) give the average weight of 6 
adult females as 302 g (267-365.8). 

ReTnarks. — The Oregon ground squirrel is abundant and widely 
distributed in the Great Basin. It is closely related to beldingi, 
and although the ranges of the two, so far as known, are not actually 
contiguous, 5^et the two forms intergrade completely in both the skin 
and sijull characters. In fact, there are numerous specimens in both 
series that are so near like certain individuals of the other race as to 
be practically indistinguishable. The distinguishing characters, 
however, are on the average well marked. The present race is 
known from specimens as far south in California as Prattville, and 
its presence has been reported at Red Clover and Mohawk, in Plumas 
County, whereas heldingi is known no farther north than Independ- 
ence Lake, on the line between Sierra and Nevada Counties, approxi- 
mately 25 miles southeast of Mohawk. 

^Specimens examined, — Total number, 405, as follows: 

California: Alturas (10 miles southwest, Modoc County), 7;*' Bald Mountain 
(8 miles south, Shasta County), 13; Bieber (Lassen County), 3; Big Mead- 
ows (10 miles west, Plumas County), !;■" Bull Meadow (Siskiyou County, 
northeast of Goose Nest Mountain), 1;^° Bunchgrass Spring (Lassen 
County), 2; Eagle Lake, 1; Feather River (North Fork, 18 miles east of 
Warner Creek), 1; Goose Lake, 3; Goose Lake Meadows (near Davis 
Creek, Modoc County), 2;^' Goose Nest Mountain (Siskiyou County), 1;" 
Grass Lake (Siskiyou County), 6;*® Hayden Hill (Lassen County), 1; 
Horse Lake, 7: Lower Klamath Lake, 1; Macdoel (Siskiyou County), 24;*' 
Madeline Divide, 5; Madeline Plains, 1; Mount Hebron (Siskiyou County), 
10; Mount Lassen (probably near Black Butte), 6; Petes Valley (Lassen 
County), 1; Pine Creek (Lassen County), 1; Pit River (North Fork), 4; 
Pit River (South Fork), 3;^' Prattville (12 miles northeast), 4; Sugar Hill 
(Modoc County), 4;" Susan River (Lassen County), 5; Susanville, 6; 
Termo (Lassen County), 1;^^ Tule Lake, 4; Tuledad Canyon (northeastern 
corner Lassen County), 1; Warner Mountains, 6; Westwood (15 miles 
west, Lassen County), 1. 

Idaho: Elba (Cassia County), l;** Hollister (Twin Falls County), 1 ; *■ Malta 
(Cassia County), 1;^' Mount Harrison (Cassia County), 1;*" Riddle (15 
miles southeast, Owyhee County), 1; Silver City, 8; Sinker Creek (Owyhee 
County), 25. 

Nevada: Badger (20 miles northwest of Summit Lake, Humboldt County), 4; 
Calico Mountain (northeastern Humboldt County), 2; Halleck (Elko 
County), 1; Massacre Creek (Washoe County), 1;** Mountain City (Elko 
County), 12; Pine Forest Mountains, 12;" Ruby Moimtains, 1; Ruby 
Valley, 10. 

Oregon: Austin (Grant County), 2; Baker (10 miles north), 3;" Barnes (Crook 
County), 3;" Bear Creek (15 miles northwest of Dayville, Grant County), 
1;** Beech Creek (Grant County), 2; Beulah (Malheur County), 13; Bu- 

^=Ten in Mus. Vert. Zool. 

*«Mus. Vert. Zool. 

^ Univ. Michigan Mus. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS §5 

chanan (Harney County), 6; Buck Creek (Crook County), 1; Burns, 2; 
Camas Prairie, east of Lakeview, 5;*^ Cedar Mountains, 1; Diamond (Har- 
ney County), 5; Disaster Peak (Malheur County), 1; Drewsey (Harney 
County), 1; Elgin, 6; Fort Klamath, 23; Harney (10 miles north), 4; 
Haycreek (Jefferson County), 13; Heppner, 15; Home (Baker County), 
10; Howard (Crook County), 4; Jordan Valley (Malheur County), 5; 
Joseph (Wallowa County), 7; Klamath Falls, 3; Lakeview, 1; Lone Rock 
(6 miles east, Gilliam County), 1; Lost River, Klamath Basin, 1; Mahog- 
any Mountain (Malheur County), 3; Malheur County, near McDermitt, 
Nev., 3; Malheur Lake, 1; Maury Mountains (Crook County), 1; Meacham 
(10 miles south, Umatilla County), 1; Mount Vernon (Grant County), 2; 
Mount Warner (=Hart Mountain, Lake County), 2; Narrows (Harney 
County), 4; Po Valley (Lost River, Klamath County), 1; Prineville, 7; 
Rattlesnake Creek (at head, Malheur County), 1; Rockville (Malheur 
County), 1; Shirk (Harney County), 1; Steens Mountains, 13; Swan Lake 
Valley (Klamath County), 2; Telocaset (Union County), 2; Twickenham 
(Wheeler County), 2; White Horse Creek (Harney County), 1. 

CITELLUS PARRYH GROUP 

CITELLUS COLUMBIANUS (Ord) 
[Synonymy under subspecies] 

SpecifiG characters. — Larger than O. richardsonii or C. armatus; 
hind foot, 48-58 mm ; tail, 80-116 ; skull length, 49.5-57. Skull rela- 
tively longer than that of richardsonii., the zygomata less widely ex- 
panded posteriorly; dorsal outline much flatter, the highest point 
behind the postorbital processes, the rostrum not sharply depressed; 
interorbital region relatively broad and flat, the supraorbital margins 
not elevated or thickened; rostrum and nasals longer; upper tooth 
rows nearly parallel; audital bullae large but not greatly elevated; 
meatus slightly produced. 

Color. — Nose and face tawny or hazel; occiput, nape, and 
sides of neck smoke gray; upper parts cinnamon buff or sayal 
brown, shaded with fuscous and in winter with smoke gray; hmd 
legs and feet tawny or hazel; front feet ochraceous buff; tail gray 
or tawny ; under parts ochraceous buff or tawny. 

CITELLUS COLUMBIANUS COLUMBIANUS (Ord) 

Columbian Ground Squirrel 

(Pis. 4; 24, A; 29, A) 

Arctomys columUanus Ord, Guthrie's Geography (2nd Amer. ed.), 2:292 

(description, p. 303), 1815. 
Anisonyx hraohiura Raflnesque, Amer. Monthly Mag. 2 : 45, 1817. 
Arctomys brachyura Hnrlan, Fauna Americana, p. 304, 1825. 
Arctomys brachyurus Richardson, Fauna Boreali-Americana, p. 151, 1S29. 
Arctomys parryi var. j8, erythrofiluteia Richardson, Fauna Boreali-Americana, 

p. 161, 1829 ("Rocky Mountains, near the sources of the Elk River"=Wolf 

Plain, 30 miles west of Rock Lake, Alberta).** 
[Spermophihis parryi] var. erythrogluteia Allen, Boston Soc. Nat. Hist. Proc. 

16: 292, 1874. 
Spermophilvs empetra var. erythroglutaeus Allen, Monog. North Amer. Roden- 

tia, p. 839, 1877 (part). 
Spermophilns rolnmhiavufi Merriam, North Amer. Fauna 5: 39, 1891. 
Citellus colnmbianuH Allen, Amer. Mus. Nat. Hist. Bull. 19:536, 1903. 
Citellus colnmbinnvs albertae Allen, Amer. Mus. Nat. Hist. BuU. 19 : 537, 1903 

(Canadian National Park, Alberta). 
CUellvs (Colobotis) columbianus Preble, North Amer. Fauna 27: 1G4, 1908. 



*' narnegie Mus. 

»o See remarks, p. 88. 



86 



NORTH AMERICAN FAUNA 



[No. 56 



Type. — None designated ; original description based on Lewis and 
Clark's description of animals taken by them on a camas prairie 
between the forks of the Clearwater and Kooskooskie Rivers, Idaho, 
Range.— ^ook^ Mountain region of western Montana, Idaho^ 
northeastern Washington, southeastern British Columbia, and west- 
ern Alberta; also the plains of eastern Washington and mountains 

of east-central Oregon 
(exclusive of the Blue 
Mountains) ; north to 
the headwaters of 
South Pine Eiver, 
British Columbia (re- 
ported by William 
Fox from this locality 
and from mountains 
on east side of the 
lower Parsnip River) ; 
south to Craters of the 
Moon, Butte County, 
Idaho, and Harney 
County, Oreg. ; east to 
Cutbank and Towns- 
end, Mont.; west to 
Shuswap and Okana- 
gan Lake, British 
Columbia, Oroville, 
Wash., and Snow 
Mountain, head of 
Silver Creek, Harney 
County, Oreg. (fig. 
7). Zonal range: 
Canadian and Hud- 
sonian. 

External charac- 
ters. — As given under 
specific characters (p. 
85) ; in comparison 
with C. parryii ple- 
sms, upper parts not 
distinctly spotted; 
sides of neck gray in- 
stead of buff; hind 
feet and legs darker 
(tawny or hazel in- 
stead of cinnamon 
buff) ; tail edged with 
white instead of buff; tail averaging longer and hind feet shorter. 
Cranial characters. — As given (p. 85) in comparison with 0. rich- 
ardsonii richardsonii. Compared with plesius: Skull averaging 
smaller and relatively narrower, the superior outline flatter (less 
convex); rostrum longer and narrower; supraorbital shelf not ele- 
vated; palate longer, its posterior border considerably behind plane 
of last molars; posterior loph of m^ low and sometimes discontinuous. 
Color. — Summer pelage: Nose and front of face tawny or hazel; 




Figure 7. — Distribution of the subspecies of Citellus colum- 
bianus: 1, C. o. columhianus ; 2, G. c. ruficaudus. 



1938] REVISION OF THE GROUND SQUIRRELS §7 

crown mixed cinnamon buff and smoke gray; occiput, nape, and 
sides of neck pale smoke gray; eye ring pale buff; ears hair brown 
on outer surface, buffy or tawny on inner surface; general tone of 
upper parts cinnamon buff or sayal brown, more or less shaded with 
the darker color of the under fur, which is fuscous or hair brown; 
sides washed with grayish or bufl'y v\'hite; under parts cinnamon 
buff or ochraceous buff; front legs and feet ochraceous buff; hind 
feet ochraceous tawny, the thighs hazel; tail above, black, rather 
heavily overlaid with grayish white and sparingly sprinkled vrith 
cinnamon buff or tawny; tail beneath, mixed fuscous black and 
grayish white. Winter pelage (March and April) : Similar to the 
summer pelage but upper parts more heavily sprinkled with grayish. 

Variation. — Two albinistic juvenile individuals were taken at Pull- 
man, Wash., May 10, 1906; Svihla (1933, p. 78) reports seeing three 
albino individuals there in 1933. 

Molt. — The annual molt occurs in June or July. A female taken 
at Ketchum, Idaho, June 6, is in a badly worn pelage, with new hair 
appearing on the forehead; another female (subad.) from Columbia 
Falls, Mont.. June 27, shows new pelage covering the head and me- 
dian dorsal region, nearly to the rump ; an adult female from Nelson, 
British Columbia, July 18, shows a patch of fresh summer pelage 
on the middle of the back; an adult female from Piegan Pass, 
Mont., is in a much worn pelage, with new hair appearing on the 
head and nape; a juvenile from ISilver, Mont., June 26, Avas acquiring 
a new pelage in patches on the head and back. In the large series 
examined no evidence has been found that would indicate a molt 
in the autumn. 

Measurements. — Average of 12 adults (G males, 6 females) from Idaho: 
Total length, 349.7 (327-377) ; tall vertebrae, 100.5 (83-116) ; hind foot, 51.2 
(48-55). Skull: Average of 10 adult males from Idaho: Greatest length, 51.7 
(50-56) ; palatilar length, 25.1 (24-27) ; zygomatic breadth, 31.8 (30.5-33.8) ; 
cranial breadth, 20.8 (19.6-21.8) ; interorbital breadth, 10.6 (9.0-12) ; post- 
orbital constriction, 11.3 (10.4-12.5) ; length of nasals, 19.4 (1&-21.4) ; maxil- 
lary tooth row, 10.9 (10.1-11.8). Average of 7 adult femal(>s from Idaho: 
Greatest length, 50.7 (49.5-51.9) ; palatilar length, 24.8 (23-26) ; zygomatic 
l>readth, 32.2 (31.6-33.6) ; cranial breadth. 21 (20.5-21.4) ; interorbital breadth, 
11.2 (10.2-12) ; postorbital constriction, 12 (11.4-12.2) ; length of nasals, 18.7 
(18-19.4) ; maxillary tooth row, 11 (10.4-11.6).. 

Weight. — Shaw (1926a, p. 137) gives the weights of two males taken in late 
July as 589 and 830 g, respectively ; eight males taken from the hibernation den 
at time of awakening averaged 492 g (43.1-571) ; two males running at large on 
March 10, after hibernation, weighed respectively, 341 and 375 g. Two females 
taken when going into hibernation weighed respectivelv, 414 and 500 g (Shaw, 
19251, p. 764). 

Remarks. — The Columbian ground squirrel is quite distinct from 
any other species and its range apparently does not meet that of 
C. parryii plesius in British Columbia. The latter reaches its south- 
ern limit in the vicinity of Tatletuey Lake, and colnmhianus ranges 
no farther nortli than the mountains lying east of Parsnip River and 
south of Peace River, tlnis leaving a gap of 160 miles or more un- 
occupied by ground squirrels of this group. In Montana and south- 
ern Idaho, this species is apparently extending its range eastward 
and southward, doubtless attracted from its natural home in the 
mountain meadows to the cultivated fields in the valleys. 

The form occupying the Blue Mountains region of Oregon and 
Wasliington is recognized as a subspecies, but nearly typical colum- 
hiccnus occurs in the low mountains south of this area and probably 



88 NORTH AMERICAN FAUNA [No. 56 

in all the surrounding foothills. Two adult specimens from moun- 
tains 10 miles north of Harney and 3 miles from Ironsides, Oreg., 
are intermediate, agreeing in color with columbianus and in skull 
characters with G. c. ruficaudus. 

Although discovered by Lewis and Clark in their epochal journey 
across the continent in 1804-6 and described by Ord in 1815, this 
species was very imperfectly known for many years, and the name 
columbianus was misapplied to the plateau prairie dog {Gynomys 
gunnisoni) . 

Richardson, 1829, named a ground squirrel procured by Drummond 
in the Canadian Rockies as a variety of the Parry ground squirrel — 
Arctomys parryi var. fi, erythrogluteia. Allen (1877) adopted Rich- 
ardson's name, listing under it two specimens from the head of 
Flathead River and two from Kootenay River — both localities in 
southeastern British Columbia. Merriam (1891, p. 39), having pro- 
cured specimens from the vicinity of the type locality of colum- 
bianus, cleared up the situation, showing that the "burrowing squir- 
rel" of Lewis and Clark was actually a ground squirrel, and that the 
names columbianus and erythrogluteia referred to the same species- 
Allen, however, in 1903, revived the name erythrogluteia and ap- 
plied it to the form of parryii occurring on the head of Telegraph 
Creek and Sheslay River, British Columbia, which he recognized 
as distinct from columbianus and wliich had been named plesius by 
Osgood in 1900. This assignment of erythrogluteia was made on the 
assumption that the type locality — Elk River, Rocky Mountains — 
is in latitude 57° N., as stated by Richardson in the original descrip- 
tion, and therefore not far from the Telegraph Creek region. This 
however, was an error, for as Preble has shown (1908, p. 164), the 
"Elk River" of Richardson is the Athabaska, and its sources are 
between 52° and 54° N. Richardson's species — erythrogluteia — was 
based on specimens collected by Thomas Drummond and the type 
locality is determined by a reading of Drummond's sketch of his 
journey published in Hooker's Botanical Miscellany (1830, p. 178). 
On page 212 of this publication he speaks of finding Arctomys parryi 
abundant "on the mountains near the Wolf's Plain" and states that 
specimens were "brought home." On page 199 he gives the location 
of Wolf Plain as "about 30 miles west from Lac-la-Pierre" ( = Rock 
Lake). Rock Lake is about 25 miles northwest of the lower end of 
Jasper Lake. This would fix the type locality of erythrogluteia 
as near the headwaters of Sulphur River, a branch of Smoky River. 
Specimens of this animal were taken by J. Alden Loring in 1895, 
on Smoky River, a short distance from this locality, and, as already 
stated, they prove to be indistinguishable from typical columbianus. 
Examination of a series from Canadian National Park that formed 
the basis of Allen's ''^albertae'''' shows their characters to be too slight 
and inconstant to admit of recognition in nomenclature. The skulls 
average slightly larger and flatter than those of typical columbianus 
and the jugal averages broader, but these characters are not constant 
in the series of 10 skulls examined; the shape of the antorbital 
foramen varies from triangular to circular. 



19381 REVISION OF THE GROUND SQUIRRELS 39 

Specimens examhied. — Total number, 351, as follows: 

Alberta: Banff, 6; [Rocky Mountains] 75 miles southwest of Calgary, 1;" 
Canadian National Park, 3; '"'■ Crows Nest (Livingstone River), 1; " Crows- 
nest Pass, 1;'^ Hay River (near head), 1; Henry House (25 miles west), 
1 ; Jasper Park, 13 ; '' '' Mount Forgetmenot, 4 : =' Ptarmigan Lake, 3 ; ^' 
Silver City, 2; °- Smoky Valley (50 miles north of Jasper House), 7; Sulphur 
River (upper), 2; Waterton Lake Park, 5.°* 

British Columbia: Barkerville, 1;'' Cascade, G;"" Cranbrook, 9;'' Deer Park, 
2 ; '- Fernie. 1 ; ^ Indianpoint Lake, 2 ; ^' Midway, 4 ; ^- Mount Queest, 2 ; "^ 
Nelson, 12 ; Okanagan, 4 ; " =^ Okanagan Falls, 2 ; "= Shuswap, 4 ; '"^ Shuswap 
River (headwaters. Gold Range), 1; Spillimachene River, 3.^ 

Idaho: Bald Mountain Ranger Station (10 miles south of Idaho City), 2; Bitter- 
root Mountains, 1;'^ Coeur d'Alene, 9; Edna (15 miles northeast of Idaho 
City), 4; Forney, 2; Fort Sherman (near Coeur d'Alene), 2; Galena (30 
miles north of Ketchum), 9; Goodrich (Adams County), 3; Idaho City, 
5; Ketchum, 17; Lardo (Valley County), 1; McKinuis (7 miles east, 
Shoshone County), 1;^ Moscow, 38; Mullan, 5; New Meadows (Adams 
County), 2; Nez Perce, 2; Packer Meadow (south of Lolo Hot Springs), 
4; Seven Devils Mountains, 2; Shafer Butte (Boise County), 6;^ Tamarack 
(Adams County), 1; Troy, 1;" Warren (Idaho County), 1. 

Montana: Bass Creek (northwest of Stevensville), 1; Carroll (Deerlodge 
County), 6; Columbia Falls, 8; Corvallis, 4; Deerlodge County, 1;^^ Flat- 
head Lake (north end), 2; Flathead River (at International Boundary), 
2; Florence, 7: Gibbon Pass (Beaverhead County), 8;^' Hamilton, 3j" 
Helena, 3; Kalispell, 4; Lolo, 3; McDermott Lake, 3; Nyack (Flathead 
County), 4: Piegan Pass (Glacier National Park), 1; Prospect Creek (near 
Thompson Falls), 1; St. Marj', 2;" Silver ( = Saltese, Missoula CoimtyJ, 
4; Sula, 1; Thompson Falls, 1; Tobacco Plains (=Gateway, Lincoln 
County), 1; Willow Creek (7 miles east of Corvallis), 1; Wisdom (20 
miles north, Beaverhead County), 4." 

Oregon: Harney (10 miles north), 4; Ironside (Malheur County), 3;" Straw- 
berry Mountains, 3. 

Washington: Calispell Lake (Pend Oreille County), 1; Calispell Peak, 2; 
Cheney, 2; Colfax, 1; Colville, 16; Gifford (Stevens County), 2; Loon Lake 
(Stevens County), 6;" Pullman, 4; Spokane, 8; Sullivan Lake (Pend 
Oreille County), 2; Williams Lake (Spokane County), 1." 

CITELLUS COLUMBIANUS RUFICAUDUS Howet.l 

Blue Mountains Gbound Squiekel 

Citellus columUanus ruficaudiis Howell, Biol. Soc. Wash. Proc. 41 : 212, Dec. 18, 
1928. 

Type. — Collected at Wallowa Lake, Wallowa County, Oreg., April 
13, 1919, by George G. Cantwell; female adult, skin and skull, no. 
231942, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 
1093). 

Range. — The Blue Mountains region of Oregon and Washington, 
from Prescott and Dayton, Wash., south to Dixie Butte, Grant 
Comity, Oreg. ; east to the AVallowa Mountains, Oreg. (fig. 7). Zonal 
range: Canadian and Hudsonian. 

External charaGters. — Similar to C. c. columbianus. but upper side 
of tail tawny (not gray) ; sides of face and usually the throat a 
deeper shade of tawny ; legs and feet darker ; hind feet longer. 

Cranial characters. — Skull similar to that of columhianus,^ but 
larger and relatively broader; zygomata more heavily built, the jugal 
wider. 



"^lAmor. JIus. Nat. Hist. 

"^2 Nat. Mu.s. Canada. 

C3 Provincial Mus., Victoria, B. C. 

"" Univ. MichiRan Mus. Zool. 

^' iJonalfl R. Dicltey coll. 

^ Cleveland Mus. Nat. Hist. 

"Montana State College. 



90 NORTH AMERICAN FAUNA [No. 56 

Color. — Summer pelage (May 28) : Forehead and face hazel; sides 
of nose and throat ochraceous buff or ochraceous tawny; eye ring 
broad, pinkish buff; occiput cinnamon buff, more or less mixed with 
smoke gray and fuscous; sides of neck (beneath eyes) and an in- 
distinct band across nape, smoke gray; dorsum cinnamon buff 
grizzled with fuscous; sides smoke gray, mixed w^ith fuscous; front 
legs and feet tawny or ochraceous tawny; hind feet deep tawny, the 
thighs russet ; tail above, deep tawny, the hairs banded subterminally 
with fuscous black and cinnamon buff ; tail beneath, mixed tawny and 
smoke gray; under parts clay color or cimiamon buff, shading to 
ochraceous tawny on throat. Winter pelage (April 13) : Similar to 
the summer pelage, but upper parts pale smoke gray, mixed with 
pinkish buff' and grizzled with fuscous; feet slightly paler tawny. 

Molt. — A female specimen from the Blue Mountains, Wash. (3,000 
feet altitude), June 16, is in badly worn condition, with new hair 
appearing on the head and nape. 

Measurements. — ^Average of 10 adults (8 males, 2 females) from the Wallowa 
Mountains, Enterprise. Elgin, and Bourne, Oreg. : Total length, 369.6 (340-410) ; 
tail vertebrae, 100.7 (80-115); hind foot, 54.2 (51-58). ^kull: Average of 8 
males (ad. and subad.) from same localities: Greatest length, 54.2 (51.5-57) ; 
palatilar length, 26.6 (24..5-28) ; zygomatic breadth, 34.1 (33.2-.35.6) ; cranial 
breadth, 21.9 (21.5-22.4) ; interorbital breadth, 12.4 (11.1-14.3) ; postorbital 
constriction, 11.9 (10.5-12.6) ; length of nasals, 19.8 (18.8-20.3) ; maxillary tooth 
ro-w, 11.4 (10.5-12.4). Average of 4 females from same region: Greatest length. 
52.9 (50.7-54.7) ; palatilar length, 25.7 (24.5-27.5) ; zygomatic breadth, 33.3 
(31.2-34.6) : cranial breadth, 21.3 (20.4-21.7) ; interorbital breadth, 12.5 (11.5- 
13.2) ; postorbital constriction, 12.1 (11.9-12.3) ; length of nasals, 19.3 (18.7- 
19.7) ; maxillary tooth row, 11.3 (11-11.8). 

Remarhs. — This race is restricted to the Blue Mountains region of 
northeastern Oregon and southeastern Washington; it intergrades 
with coluTnbianus in the Strawberry Mountains and on the southern 
slopes of the Burnt River Mountains, Oreg. 

Specimens examined. — Total number, 69, as follows : 

Oregon: Anthony (6 miles southwest of Cornucopia), 16;"^ Austin (Grant 
County), 1; Bourne (Baker County), 3; Cornucopia (Baker County), 7; 
Dixie Butte (Grant County), 6; Elgin, 5; Enterprise, 2; Joseph, 1 :™ 
Meacham, 4 ; "Wallowa Lake, 7. 

Washington: Anatone (Asotin County), 2; Blue Mountains (21 miles south- 
east of Dayton), 4; Dayton, 4;'' Prescott, 7.**'" 

CITELLUS PARRTII (Richardson) 
[Synonymy under subspecies] 

Specific characters. — Size medium to large; hind foot, 50-68 mm; 
tail, 77-138 ; skull length, 50.7-65.7. Skull heavily built and angular, 
its superior outline convex, highest at plane of postorbital processes ; 
the rostrum and brain case moderately depressed; zygomata broad 
and heavy, widely spreading and strongly twisted from the vertical 
plane ; postorbital processes heavy, depressed, directed slightly back- 
wards; supraorbital shelf thickened and elevated; nasals broad, 
ending about even with premaxillae; antorbital canal large, orbic- 
ular, with a pronounced process at its anterior opening; audital 
bullae broad, moderately inflated, the meatus tube moderately pro- 
duced; molariform teeth heavy, the anterior upper premolar {p^) 



ssAmer. Mus. Nat. Hist. 
"^ Univ. Michigan Mus. Zool. 
««Mus. Vert. Zool. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



91 



one-third to nearly one-half of p*; i)osterior loph on m^ well de- 
veloped (but lower than anterior loph) and continuous (not broken 
by a sulcus in middle) ; incisors relatively slender and projecting 
forward. 

Color. — Head tawny or cinnamon; rest of upper parts red- 
dish brown, cinnamon, or fuscous, more or less abundantly flecked 
with rather large whitish spots; under parts ochraceous tawny to 
cinnamon buff in summer pelage, ochraceous buff or grayish white in 
winter; sides of head and body buff or tawny in summer, becoming 
smoke gray in winter; feet and legs tawny, ochraceous buff, or cin- 
namon; tail above, ochraceous tawny, cinnamon, or cinnamon buff, 
more or less mixed with fuscous black ; tail beneath, russet or tawny. 



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Figure 8. — Distribution of the species and subspecies of the Citellus parryii group : 1, 
C. p. parryii; 2, C. p. banoice7inis ; 3, C. /'. plesiusj 4, C. p. abltisus ; 5, C. p. nebulicola; 
6, G. kodiacenais ; 7, O. oagoodi; 8, C. p. lyrattis. 

CITELLUS PARRYII PARRYII (Richakdson) 

Fabry's Ground Squiebel 

Arctomys parryii Richardson, Appendix to Parry's Second Voyage, p. 316, 1825 

(1827). 
Spermophilus parryii Lesson, Manuel de Manim., p. 244, 1827. 
Arctomys {Spermophilus) parry i Richardson, Fauna Boreali-Amer. 1: 158, 1829. 
Arctomys parry i var. phaeognatha Richardson, Fauna Boreali-Amer. 1 : 161, 

1829 (Hudson Bay). 
A[rctomys] kennicottii Ross, Canad. Nat. & Geol. G: 434, 1861 (Fort Good Hope, 

Mackenzie). 
Spermophilus empetra Allen, Monog. North Amer. Rodentia, p. 839, 1877 (not 

Mus empetra Pallas). 
Spermophilus parryi Preble, North Amer. Fauna 22 : 46, 1902. 
Citellus parryii Miller and Rehn, Boston Soe. Nat. Hist. Proc. 31 : 75, 1903. 
Citellus (Colobotis) parryi kennicotti Preble, North Amer. Fauna 27: 162, 1908. 
Citellus (Cololotis) parryi Preble, in Seton, The Arctic Prairies, app. F., p. 

342 1911. 
Citellus parryi kennicottii, Hall, Calif. Univ. Pubs., Zool. 30 : 423, 1929. 

Type. — None designated; description based on specimens collected 
at Five Hawser Bay, Lyon Inlet, Melville Peninsula, Hudson Bay, 
Canada. 

Range. — Barren Grounds of northern Canada from Melville Penin- 
sula and western shores of Hudson Bay west to northwestern Yukon 



92 ' NORTH AMERICAN FAUNA [No. 56 

and northeastern Alaska ; south to Rampart House on Alaska- Yukon 
boundary, Artillery Lake, Mackenzie, and a point about 25 miles 
south of Cape Eskimo, Hudson Bay ^^ (fig. 8). Zonal range: Arctic. 

External characteTS. — Size large; entire head (in summer) tawny 
or russet; upper parts brownish, more or less mixed with gray and 
flecked with large, irregular, whitish spots ; tail russet beneath, edged 
with cinnam^on; under parts tawny; winter pelage much paler and 
more whitish, the under parts ochraceous buff or grayish white. 

Cranial characters. — As given under specific characters (p. 90) ; 
skull large, equaling that of G. osgoodi; much larger than that of 
G. p. plesius; temporal ridges uniting in adults to form a prominent 
sagittal crest. 

Color. — Summer pelage (Hudson Bay, 25 miles south of Cape 
Eskimo, August) : Top of head (nose to occiput) russet or tawny; 
sides of nose and face cinnamon buff or ochraceous buff; eye ring 
(often indistinct) pinkish buff or cartridge buff; sides of neck 
tawny, shaded with fuscous black; dorsum russet or bister, abun- 
dantly flecked with rather large, irregular spots of creamy white or 
buffy white; front and hind legs tawny or ochraceous tawny, the 
feet ochraceous buff; under parts ochraceous tawny, becoming cin- 
namon buff on the throat; tail above, blackish, shaded on proximal 
half with ochraceous tawny or hair brown and sparingly edged with 
ochraceous tawny or avellaneous; tail beneath, russet, widely bor- 
dered at tip with blackish. Winter pelage (Dolphin and Union 
Strait, Arctic coast. May) : General tone of upper parts pale smoke 
gray, sparingly sprinkled with black hairs and shaded with sayal 
brown in the middle of the back ; top of head and face cinnamon or 
pinkish cinnamon; under parts pinkish buff or ochraceous buff; 
tail above, smoke gray, mixed with cinnamon buff, the tip blackish; 
legs and feet pinkish buff, pinkish cinnamon, or ochraceous buff. 

Variation. — Several young specimens from Artillery Lake, 
Mackenzie (U. S. Natl. Mus. nos. 180894, 180895, Aug. ^6), differ 
from Hudso]! Bay specimens taken at the same season in having 
the back of a grayish tone, produced by a mixture of fuscous and 
grayish white. An adult (no. 180922) from the same locality, but 
without date, is of the normal brownish color. A series of subadult 
specimens from Clinton Golden Lake and Thelon River, Mackenzie, 
taken in early August, are in worn pelage distinctly paler and 
more grayish tlian the August specimens from the coast of Hudson 
Bay. An adult from Gollinson Point, on the north coast of Alaska 
(Sept. 30) has tlie under parts grayish white, very faintly washed 
with pale pinkish buff; others from the same section at the same 
season have the under parts partly white and partly ochraceous 
buff. Several summer specimens from Cape FuUerton, Hudson Bay, 
have the head and sides of neck heavily washed with bay or chestnut 
and others from the northeast coast of Alaska have a less intense 



81 A specimen in the National Museum of Canada, collected by Owen O'Sullivan and 
labeled as from "Lat. 53° N., Long. 83° W." indicates a southward extension of the ani- 
mal's range to a point on the west side of James Bay ; Dr. R. M. Anderson has kindly 
looked up the records of O'SuUivan's trip (Canada Geol. Survey Summary Kept., 190S, 
no. 1072, 1909, p. 93) and he finds no reason to doubt that the specimen was taken at 
the point indicated by the label. In view of the fact, however, that other explorers have 
failed to find any evidence of the occurrence of this species at either Fort Churchill or 
York Factory, the record from James Bay is most surprising, and suggests the possibility 
of error. 



1938] REVISION OF THE GROUND SQUIRRELS 93 

wash on the head and a broad streak of chestnut on the middle 
of the belly. 

Molt. — The spring molt takes place chiefly in June but the process 
is clearly shown by only a few of the specimens examined. An adult 
male from Firth River, Alaska- Yukon boundary, June 24, 1912, 
is in badly worn winter pelage, with the new summer pelage showing 
in patches on the nape and back ; another adult male from U Creek, 
Alaska, June 27, shows new pelage covering the head, fore legs and 
portions of the belly. An adult female from Old Fort Good JHope, 
June 27, is acquiring a fresh pelage of a grayish tone on the upper 
parts, the under parts apparently in complete summer pelage, but 
the tail hairs not fully renewed. An adult female from Clinton 
Colden Lake, Mackenzie, August 2, is in greatly worn pelage, with 
new hair of a grayish tone coming in on the shoulders, and patches 
of new buffy hair on the under parts. The fall molt occurs in 
September or October, and as usual in this genus, the change is 
obscurely indicated. Two specimens from Collinson Point, Alaska, 
taken September 22 and 24, 1913, show the winter pelage cover- 
ing the head, shoulders, fore back, and most of the under parts, 
the moderately worn suimner pelage still remaining on the hinder 
back and on the middle of the belly. 

Measurements. — Average of 8 adult males from the Arctic coast of Mack- 
enzie (Corouatiou Gulf to Franklin Bay) : Total length, 443 (420-495) ; tail 
vertebrae, 124 (115-13G) ; hind foot, C5.6 (G3-68). Average of 5 adult females 
from same localities: Total length, 414 (890-430) ; tail vertebrae, 122.6 (9S- 
13S) ; hind foot, 50.2 (57-61). Average of 9 adult males from Aylmer and 
Clinton Colden Lakes and near Cape Eskimo, Mackenzie : Total length, 4U0 
(380-430); tail vertebrae, 125 (115-140); hind foot, 63.6 (60-66). Skull: 
Average of 6 adult males from west coast of Hudson Bay (Cape Fullertou 
and Cape Eskimo) and Aylmer and Clinton Colden Lakes, Mackenzie : Greatest 
length, 60.9 (60-62.2) ; palatilar length, 31.2 (30.3-32.5) ; zygomatic breadth, 
402 (39.3-42) ; cranial breadth, 24.7 (23.5-25.5) ; interorbital breadth, 13.4 
(12.9-13.8) ; postorbital constriction, 13.4 (12.7-14.1) ; length of nasals, 23.6 
(21.0-25.1); maxillary tooth row, 13.6 (13.2-14.1). Average of 4 old adult 
males from Dolphin and Union Strait, Arctic coast : Greatest length, 64.3 
(63.3-65.7) ; palatilar length, 33.2 (33-33.5) ; zygomatic breadth, 42.8 (40.6- 
44.1) ; cranial breadth, 25.4 (24.7-26.4) ; interorbital breadth, 14.9 (14.3-15.6) ; 
postorbital constriction, 12.9 (12.4-13.3) ; length of nasals, 25 (23.7-25.9) ; 
maxillary tooth row, 14.1 (13.7-14.3). Average of 6 adult females from west 
coast of Hudson Bay and interior Mackenzie: Greatest length, 57.5 (55.4-59.5) ; 
palatilar length, 29.6 (20-30.5, 3 specimens); zygomatic breadth, 37.6 (35.8- 
39.4) ; cranial breadth, 23.5 (22.8-24.2) ; interorbital breadth, 12.9 (12.5-13.4) ; 
postorbital constriction, 134 (11.7-14.3); length of nasals, 21.5 (20-22.9); 
maxillary tooth row, 13.3 (12.4-13.7). Average of 4 old adult females from 
Arctic coast (Dolphin and Union Strait and Coronation Gulf) ; Grealest 
length, 61.2 (60.7-62.1); palatilar length, 31.9 (.31.5-32); zygomatic breadth, 
40.9 (40.5-41.5) ; cranial breadth, 24.5 (24.2-24.9) ; interorbital breadth, 13.6 
(12.0-14.4) ; postorbital constriction, 13.1 (12.2-13.7) ; length of nasals, 23.4 
(23.2-24) ; maxillary tooth row, 13.8 (13.4-14.2). 

Weight.— K male taken at Collinson Point, Alaska, September 9, weighed 
2 pounds, 4 ounces ; another male from the same locality, September 7, weighed 
2 pounds, 8 ounces; and a female taken there October 2, weighed 1 pound, 
9 ounces. 

Remarks. — Although described more than a hundred years ago, this 
large ground squirrel, until recently, has been imperfectly known 
and poorly represented in collections. Even now, although a series 
of over 100 specimens has been brought together, there is a lack of 
material in unworn summer pelage, which fact makes it difficult 
to describe the pelage variations. The species exhibits a very con- 



94 NORTH AMERICAN FAUNA [No. 56 

siderable amount of both individual and seasonal variation and 
from only a few localities are there unworn specimens illustrating 
both the summer and the winter pelages. Specimens in fresh winter 
pelage are lacking from Hudson Bay and the entire region east of 
Coronation Gulf. A series from Cape Fullerton, Hudson Bay — some 
225 miles southwest of the type locality — undoubtedly represents 
the typical form. These are without date of capture (excepting one 
marked October) but apparently were taken in late summer (August 
or September) . Most of them show considerable wear. Two adults 
in slightly worn summer pelage and two full grown young of the 
year in unworn pelage taken near Cape Eskimo, Hudson Bay, Aug- 
ust 10 and 11, 1900, are slightly darker above than the average of the 
Cape Fullerton specimens, the back less strongly flecked with whitish 
spots. These Cape Eskimo specimens, however, are considered typi- 
cal and have been used in making comparisons; they may be very 
closely matched in a large series taken in July and August on Firth 
Eiver, northwestern Yukon, about 45 miles from the Arctic coast. 
The skulls of these Yukon specimens average slightly smaller than 
the series from Hudson Bay but are essentially like them in their 
characters. 

Variation in size of skull is extreme in this species. Eight very 
old specimens (four males, four females) in a series from the vicinity 
of Coronation Gulf, Arctic coast, are decidedly larger than any 
others examined. Probably this excessive size is due to the age of the 
animals, and a larger series, including some subadults, would doubt- 
less show a smaller average. Nine adult males of a series from Firth 
River, on the Alaska- Yukon boundary (which, as stated above, agree 
in color with parity ii from Hudson Bay) average slightly smaller 
than either the Hudson Bay series or those from the Alaska coast. 

The disposition of the name kennicotfii, proposed by Ross in 1861 
is made difficult by the lack of comparable material from the type 
locality, which, as shown by Preble (1908, p. 162), is "the lower 
Mackenzie region", in the vicinity of Old Fort Good Hope and 
Anderson River. Unfortunately, there are available only three 
summer specimens from this section, one from Old Fort Good Hope, 
taken June 27, one from Lockhart River, without date, and one from 
Anderson River, August 1. The Anderson River specimen is an 
immature individual m a much worn pelage, but is clearly referable 
to parryii, the under parts being of the same tawny color ; the Lock- 
hart River specimen is in a worn (summer?) pelage, with very indis- 
tinct spotting; the under parts and sides are ochraceous buff, con- 
siderably paler than in typical parryii; the Fort Good Hope speci- 
men was apparently acquiring summer pelage; it is paler on the 
head, tail, sides, and under parts than typical pan^yii; the upper 
parts are of a uniform brownish gray tone, practically without 
spotting; possibly this individual, which in size and cranial char- 
acters agrees with parryii, represents approach to the subspecies 
plesius^ which occupies the mountainous regions west of the Mac- 
kenzie Valley; the same may be said of two specimens from Fort 
McPherson, which are slightly paler than parinjii and have smaller 
skulls. 

Preble (1908, p. 162) has set uj) ^''ItennicottiP as a subspecies of 
parryii^ considermg it to be identical with C. p. 'bai^roicensis, but 
the recent acquisition of a lai'ge series of the latter form from Point 



1938] REVISION OF THE GROUND SQUIRRELS 95 

Hope, Alaska, shows it to be decidedly paler than typical 'parryii and 
paler even than the specimens representing "kennicoitii." In con- 
sideration also of the occurrence of practically typical parryii in 
the mountains along the Alaska- Yukon boundary, lying to the west- 
ward of the Mackenzie Valley, it seems probable that when a larger 
series from the type region of '■^kennicottii'^ is made available, they 
will be shown to be referable to parryii. 

The almost complete absence of specimens in summer pelage from 
the Arctic coast of Mackenzie and Alaska makes it difficult to deter- 
mine with certainty the western limits of the present form on that 
coast. However, since the series in summer pelage from Firth River, 
Yukon, some 45 miles back from the coast, is clearly referable to 
parryii, it seems reasonable to consider that the specimens in winter 
pelage from the northeast coast of Alaska, as far west as CoUinson 
Point, are of the same race. No specimens are available between 
Collinson Point and Point Barrow. 

/Specimens examined. — Total number, 205, as follows : 

Alaska: Collinson Point, 11;"^ Hula Hula River, 8;"^°^ International Boundary, 
80 miles north of Porcupine River, 1 ; Okpilak River (west of Barter 
Island), 4;^ Porcupine River (12 miles below Coleen River and near Salmon 
Trout River), 4; Sadlerochit River, 2."^ 

Northwest Territories [Mackenzie]: Anderson River, 2; Artillery Lake, 16 (3 
skins with skulls, 13 skulls only) ;" Aylmer Lake, 9*^ (skulls) ; Bernard 
Harbor (Dolphin and Union Strait), 25;*' Clinton Golden Lake, 10; Cop- 
permine River (mouth), 3;"' Cape Eskimo, 3;^ Cape Fullerton, 9;*" Coro- 
nation Gulf, 6 ; ^'^ ** Deas Thompson Point, 1 ; *' Dease Bay, Great Bear 
Lake, 2;" Fort Anderson, 7 (1 skin, 6 skulls only) ; Fort Good Hope, 2; 
Fort McPherson, 2; Hanbury and Thelon Rivers (junction), 5;" Hudson 
Bay (25 miles south of Cape Eskimo), 4; Kasha Lake, 2; Langton Bay 
(arm of Franklin Bay), S;*^ Lockhart River, 2; "Mackenzie" (no labels), 
7 ; '' Mackenzie River Delta, 3 ; ^' Marble Island, 1 ; Old Fort Good Hope, 4. 

Yukon: Firth River (on 141st. meridian), 15: Joe River (Firth River), 17; 
Old Crow River (mouth, and 50 miles above Timber Creek), 11; Rampart 
House, 2; U Creek (90 miles north of Rampart House), 2. 

CITELLUS PARRYII BARROWENSIS (Meemam) 

Babeow Ground Sqtjibbel 

Bpermophilus harrowcnsis Merriam, Wash. Acad. Sci. Proc. 2 : 19, Mar. 14, 1900. 
Spermophilus beringensis Merriam, Wash. Acad. Sci. Proc. 2: 20, 1900 (Cape 
Lisburne, Alaska). 

Type. — Collected at Point Barrow, Alaska, May 30, 1883, by Lt. 
P. H. Ray ; male adult, skin and skull ; no. if§4i, U. S. Natl. Mus. 
(orig. no. 1428). 

Range. — Arctic coast of Alaska from Point Hope eastward at least 
to Point Barrow; limits of range not known (fig. 8). Zonal range: 
Arctic. 

External characters. — Similar to C. p. parryii, but coloration paler, 
both above and below; top and sides of head, sides of neck, and 
thighs paler (less reddish) ; similar in color to C. p. ablusus, but 
upper parts averaging paler (less brownish) ; sides of body more 
tawny (less grayish), and under parts slightly darker. 

•"Natl. Mu.s. Canada. 

•^Amer. Mus. Nat. Hist. 

"* Twelve in Amer. Mus. Nat. Hist. 



95 NORTH AMERICAN FAUNA [No. 56 

Cranial characters. — Skull essentially like that of parryii. 

Color. — Summer pelage (August) : Top of head (nose to occiput) 
tawny or russet; sides of face cinnamon buff; sides of neck ochra- 
ceous tawny ; upper parts sayal brown or mikado brown, abundantly 
and coarsely flecked with whitish or warm buff spots ; nape and fore- 
back washed with grayish white ; legs cinnamon ,*■ feet cinnamon buff ; 
tail tawny or mikado brown, more or less mixed above with black, tip 
wholly black; under parts cinnamon or cinnamon buff. Winter 
pelage (October-May) : Coloration of upper parts and sides more 
grayish than in summer ; sides of nose pinkish buff ; feet paler than 
in summer, sometimes pinkish buff; under parts cinnamon buff or 
pinkish buff. 

Molt. — The spring molt is not shown by any of the specimens ex- 
amined, but probably it occurs in June, as in the other races. 

Measurements. — Average of 11 adult males from Point Hope, Alaska : Total 
length, 411.6 (383-440) ; tail vertebrae, 118.6 (107-142) ; liind foot, 65 (61-68) ; 
ear from notch (dry), 7.6 (6-9). Average of 10 adult females from Point 
Hope: Total length, 390.2 (368-^20); tail vertebrae, 113.2 (101-127); hind 
foot, 61 (59^65) ; ear from notch (dry), 6.7 (6^7). Skull: Average of 12 adult 
males (Point Barrow, 7; Point Hope, 5): Greatest length. 60.9 (58-62.9); 
palatilar length. 32 (30.8-33) ; zygomatic breadth, 40.4 (38.1-42.2) ; cranial 
breadth, 24.4 (24.2-25.1) ; iuterorbital breadth, 13 (12.1-13.5) ; postorbital con- 
striction, 13.9 (13-15.5) ; length of nasals, 23 (21.3-25.4) ; maxillary tooth row, 
33.9 (13.2-15). Average of 6 adult females (Point Barrow, 2; Point Hope, 4) : 
Greatest length, 59.1 (57.8-60.8) ; palatilar length, 30.9 (30-31.8) ; zygomatic 
breadth, 39.7 (37.9-41.2) ; cranial breadth, 23.2 (22.4-24.1) ; Interorbital 
breadth, 12.9 (12.2-14.6) ; postorbital constriction, 12.7 (12-14.4) ; length of 
nasals, 21.9 (20.9^23.1) ; maxillary tooth row, 13.4 (13-13.9). 

Remarks. — The ground squirrels inhabiting the northwest coast of 
Alaska are distinctly paler than typical parryii from Hudson Bay. 
The series of eight summer skins from Point Barrow agrees essen- 
tially with a large series from Point Hope, recently collected by 
R. M. Gilmore for the Museum of Vertebrate Zoology; hence the 
name C. p. heHngensis.^ based originally on two skins without skulls 
from Cape Lisburne, is placed in the synonymy of C. p. harrotoensis., 
the latter name having page priority. The subspecies ranges east- 
ward on the coast at least to Point Barrow and possibly farther, but 
no specimens have been seen from points between Point Barrow and 
Collinson Point. The majority of the specimens available from the 
Arctic coast of northeastern Alaska and Mackenzie are in winter 
pelage, in which pelage the characters are less pronounced; a good 
series in summer pelage is needed to determine with certainty the 
limits of range of the two races, parryii and harroioensis. 

Specimens examined.- — Total number, 69, as follows: 

Alaska: Cape Lisburne, 4 (2 skins, 2 separate skulls) ; Cape Thompson, 1 ;^' 
Point Barrow, 31 (15 skins; 16 extra skulls) ; Point Hope, 30"; Wain- 
wright, 2 " ; Wainwright Inlet, 1. 

«= Mus. Vert. Zool. 

«« Twenty-eight in Mus. Vert. Zool. 

«^ Colorado Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 97 

CITELLUS PARRYII PLESIUS (Osgood) 

Yukon Ground Sqtjibbel 

(Pis. 24, D; 29, D) 

Spermophiltis empetra plesius Osgood, North Amer. Fauna 19: 29, Oct. 6, 1900. 
Ciitellusl plesius Osgood, Biol. Soc. Wash. Proc. 16: 25, 1903. 
Citellus erythrogluteius Allen, Amer. Mus. Nat. Hist. Bull. 19: 534, 1903 (not 
Arctomys parryi var. j8 erythrogluteia Richardson). 

Type. — Collected at Bennett City, head of Lake Bennett, British 
Columbia, June 19, 1899, by W. H. Osgood; female adult, skin and 
skull, no. 98931, U. S. Natl. Mus. (Biological Survey collection) 
(orig. no. 465), 

Rmige. — Northwestern British Columbia, greater part of Yukon 
(except extreme northern part) and mountainous parts of Mackenzie 
(west of the Mackenzie River) ; north to the Ogilvie Range (head 
of Coal Creek), Yukon; east to Fort Liard and the Nahanni Hills, 
Mackenzie; south to vicinity of Tatletuey Lake, British Cohunbia; 
west to Glacier, British Columbia, and Delta River (Ober Creek), 
Alaska (fig. 8). Zonal range: Hudsonian. 

External characters. — Similar to G. p. 'parryii^ but decidedly 
smaller; coloration much paler and more grayish (less tawny) above; 
sides, under parts, and feet paler ; dorsal spots smaller. 

Cranial characters. — Skull similar to that of parryii^ but much 
smaller; rostrum and nasals shorter; zygomata less widely expanded; 
frontal shield less elevated; temporal ridges less distinctly lyrate than 
in C. p. lyratus and C. kodiacensis, but not united posteriorly in a 
prominent crest as in C p. ahlusus. Teeth similar; posterior loph on 
m^ usually continuous and well developed. 

Color. — Summer pelage: Head and front of face tawny or sayal 
brown ; sides of nose clay color or cinnamon buff ; sides of head and 
neck ochraceous tawny or cinnamon buff, mixed with fuscous; gen- 
eral tone of upper parts buffy gray, caused by a mixture of fuscous, 
pinkish buff, and grayish white (the hairs being fuscous subter- 
minally and tipped with whitish or pinkish buff) ; back moderately 
sprinkled with grayish white, squarish spots (sometimes indistinct 
or nearly obsolete) ; sides and under parts ochraceous tawny or cin- 
namon buff; feet cinnamon, cinnamon buff, or clay color; tail above 
mixed cinnamon and fuscous, becoming fuscous black on distal half, 
and edged with pinkish buff; tail beneath, tawny or pale russet, the 
tip fuscous black. Winter pelage (Sept. 19) : Upper parts and sides 
pale smoke gray shaded with fuscous and washed in middle of back 
with cinnamon buff; under parts grayish white, thinly washed with 
pinkish buff; otherwise as in summer. 

Molt. — The spring molt takes place in late June; two specimens 
from Bennett, British Columbia, June 18 and 22, are in badly worn 
winter pelage, with new pelage covering the head, nape, and most 
of the under parts. Specimens showing the fall molt are not avail- 
able, but one from Bennett taken September 19 is apparently in full 
winter pelage. 

Measurements. — Average of 10 adult males from type locality : Total length, 
339.2 (320-363) ; tail vertebrae, 95.5 (85-105) ; hind foot, 54 (50-57). Average 
of 8 adult females from Bennett, British Columbia, and head of Coal Creek, 
Yukon: Total length, 329 (300-352) ; tail vertebrae, 90.4 (85-102) ; hind foot, 
52.9 (52-54). SlcuU: Average of 10 adult males from type locality: Greatest 

154970—38 7 



gg ' NORTH AMERICAN FAUNA [No. 56 

length, 53.5 (51.5-56.4) ; palatilar length, 26.2 (25-28) ; zygomatic breadth, 
34.6 (33.5-35.5) ; cranial breadth, 22.5 (21.4-23.3) ; interorbital breadth, 11.2 
(10.2-12.2) ; postorbital constriction, 13.2 (12.6-13.7) ; length of nasals, 19 
(17.7-20.7) ; maxillary tooth row, 12 (11.4-12.4). Average of 10 adult females 
from type locality: Greatest length, 52 (50.7-53.3) ; palatilar length, 25.5 (25- 
26) ; zygomatic breadth, 33.5 (32.2-^4.9) ; cranial breadth, 21.6 (21.1-22.1) ; 
interorbital breadth, 10.5 (10-11.4) ; postorbital constriction, 12.6 (11.9^13.1) ; 
length of nasals, 18.7 (18.1-19.8) ; maxillary tooth row, li;7 (11.1-12.3). 

Weight. — An adult female (Chitina River, Alaska) weighed slightly over one 
pound (no embryos). 

Remarks. — The Yukon ground squirrel is distinguishable from 
parryii and G. osgoodi by its smaller size and paler coloration. It 
occupies the greater part of the Province of Yukon (except the por- 
tion north of the Porcupine River) as well as parts of Mackenzie 
and British Columbia, and ranges westward into Alaska, where it 
merges into the subspecies dblusus. Southward it does not reach the 
range of G. columbianus. 

Specimens from the headwaters of Telegraph Creek and Sheslay 
River, northern British Columbia, were assigned by J. A. Allen 
(1903a, p. 534) to Gitellus erythrogluteius (Richardson) on the as- 
sumption that its type locality — "head of Elk River, Rocky Momi- 
tains" — is in latitude 57°, as indicated by Richardson. As shown, 
however, on page 88, the Elk River of Richardson is the Athabaska, 
whereas the type locality of erythrogluteia is actually near the head- 
waters of Sulphur River, Alberta. 

Specimens examined. — Total number, 158, as follows : 

Alaska: Chitina River Glacier, 4;** Ober Creek (Jarvis Creek, Delta River 
region), 2; Tanana Crossing, 1; Tanana Hills, 2; White Pass, 5. 

British Columbia: Bennett, 38; Chapa-atan River (Stikine River, near head), 8; 
Cassiar Mountains (near Dease Lake), 2; Ispatseezeh River (Stikine River, 
near head), 3; Klappan River Valley (near head), 1; Little Klappan River 
(headwaters), 1; McDame Creek (Dease River), 3; McKee Creek, Atlin 
District, 1;°* Rapid River (Dease River), 1; Sheep Mountain (Dease 
River), 2; Sheslay River (timber line, 4,000 feet altitude), 1; Tatletuey 
Lake, 1; Telegraph Creek (near head), 6; Wilson Creek, Atlin District, 5.*" 

Northwest Territories [Mackenzie] : Fort Liard, 1 ;™ Fort Norman (mountains 
west), 1; Fort Simpson [probably from Nahanni Hills], 1;" Mackenzie 
Mountains, 2." 

Yukon: Coal Creek (near head), 18; Donjek River, 2; Livingston, 1;" Pelly 
Lake, 1; Pelly River (Lapie River), 6; Tantalus, 1;** Teslin Lake (and 
vicinity), 25;°' Yukon River, 17 (Caribou Crossing, 6; Fifty-mile River, 1; 
Lake Lebarge, 2; Lake Marsh, 6; Miles Canyon, 1 ; Rink Rapids, 1). 

CITELLUS PARRYII ABLUSUS Osgood 

Aleutian Geound Squirrel 

Gitellus plesius ablusus Osgood, Biol. Soc. Wash. Proc. 16: 25, Mar. 19, 1903. 
Gitellus stonei Allen, Amer. Mus. Nat. Hist. Bull. 19 : 537, 1903 ( Stevana Flats, 

near Port Moller, Alaska Peninsula (not Wraugell), Alaska). (Allen, op. 

cit. p. XVII). 

Type. — Collected at Nushagak, Alaska, September 16, 1902, by 
W. H. Osgood and A. G. Maddren; male adult, skin and skull, no. 
119815, U. S. Natl. Mus. (Biological Survey collection) (orig. 
no. 2043). 



«8Natl. Mus. Canada. 

** Provincial Mus., Victoria, B. C. 

''"Univ. of Michigan Mus. Zool. 

■^ Field Mus. Nat. Hist. 

^2 Amer. Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS QQ 

Range.— Alaska, mainly south of the Yukon Valley ; north on the 
coast to Eschscholtz Bay; west on the Alaska Peninsula to its tip; 
south to base of the Kenai Peninsula ; east to headwaters of Tanana 
River; introduced on Unalaska, Uninak, and Kavalga Islands (fig. 8). 
Zonal range: Hudsonian and Arctic. 

External characters. — Similar in color to 0. p. plesius but upper 
parts (in summer) more brownish (less grayish) ; dorsal spotting 
less distinct and spots smaller; under parts averaging paler; tail 
usually more blackish, the under surface a slightly darker shade of 
russet; skull larger and relatively narrower. Compared with C. p. 
parry ii: Size much smaller; dorsal spots smaller; coloration paler, 
especially on the under parts, sides of neck legs, and mider surface of 
tail. Compared with G. p. harrowensis : Size smaller; coloration of 
upper parts darker (more brownish) ; sides paler (less tawny) ; under 
parts averaging j)aler. 

Cranial characters. — Skull larger than that of plesius, with rela- 
tively narrower brain case ; rostrum and nasals longer ; audital bullae 
larger — both longer and broader — but rather flat; temporal ridges 
less distinctly lyrate in shape than in G. p. lyratus and G. kodi- 
accTisis, uniting posteriorly to form a slight crest; skull decidedly 
smaller than that of haj-^rowensh or pai^yii. 

Golor. — Summer pelage: Top of head and face russet or tawny; 
sides of head pinkish buff or cinnamon buff, shaded with fuscous; 
front legs and sides of neck tawny; upper parts walnut brown, 
washed on neck and shoulders with pale buff, and abundantly flecked 
with irregular, buffy white spots ; fore and hind feet clay color ; tail 
above, mixed cinnamon buff and fuscous black, becoming solid 
blackish on distal fourth ; tail beneath, russet or tawny ; under parts 
clay color or cinnamon buff. Worn lointer pelage: General tone of 
upper parts snuff brown, washed on neck and shoulders with pale 
smoke gray; sides of head and neck smoke gray; sides of body pale 
buff mixed with white; under parts gi-ayish white, faintly washed 
with pinkish buff; otherwise as in summer. 

Molt. — The beginning of the spring molt is shown by an adult male 
specimen taken June 16 at Lake Aleknagik, Alaska ; new hair is ap- 
pearing on the head, shoulders, and fore legs, the rest of the body 
being in worn winter pelage. 

Measurements. — Average of 8 adult males from Nushagak and Swau Lake, 
Alaska: Total length, 874.5 (SHD^SIM) ; tail vertebrae, 102.8 (05-108); hind 
foot, 58.5 (55-61). Average of 6 adult females from same localities: Total 
length, 346.3 (340-356) ; tail vertebrae, 99.5 (95-108) ; hind foot, 56.2 (55-59). 
Skull: Average of 7 adult males from Nushagak, Alaska: Greatest length, 57 
(55.7-58.8) ; palatilar length, 28.4 (27-29.5) ; zygomatic breadth, 36.7 (35.4^ 
38.5) ; cranial breadth, 23 (22.6-23.7) ; iuterorbital breadth, 12.G (11.6-14) ; 
postorbital constriction, 13.3 (12.3-14) ; length of nasals, 21.1 (19.8-22.6) ; 
maxillary tooth row, 12.3 (11.8-12.9). Average of 7 adult females from Nush- 
agak: Greatest length, 55.3 (54.2-57.1); palatilar length, 27.7 (27-29); zygo- 
matic breadth, 35 (33.8-36.4) ; cranial breadth, 22.2 (21.5-22.5) ; iuterorbital 
breadth, 12.1 (11-5-13) ; postorbital constriction, 13 (12-14) ; length of nasals, 
12 (11.4-12.4). 

Remarks. — The Aleutian ground squirrel is closely related to 
plesius, with which it intergrades in eastern Alaska. Material is 
lacking to show the exact limits of its range eastward. Certain 
specimens from Nome, on the Seward Peninsulaj show approach to 
harrowensis in their larger skulls; intergradation with that race 
doubtless occurs between Eschscholtz Bay and Point Hope. 



IQQ NORTH AMERICAN FAUNA [No. 56 

Comparison of the type of C. ^^stonei'^ and a good series from the 
type region with typical ablusus shows no characters to separate the 
two forms. Hence '■^stoneP (supposed at the time it was described 
to have come from Wrangell, Alaska) falls in the synonymy of C. p. 
ablusus, Avhich has several months' priority. 

In the summer of 1913, 18 ground squirrels of this subspecies were 
captured at Nushagak and shipped to St. George Island in a single 
large crate. 

Although plentifully supplied with green food, they preyed on each other, and 
while this tendency was overcome to some extent by supplying them with meat, 
the stock of 18 had been reduced to 5 before they reached their destination. 
These five, an adult and four young, including both sexes, were liberated on St. 
George ; at least two survived until May 1914, but by the summer of that year 
all apparently had disappeared (Osgood, Preble, and Parker, 1915, p. 129). 

This subspecies is closely similar to C. huxtoni (Allen, 1903c, p. 
139) of eastern Siberia, differing chiefly in less intensely tawny 
coloration, and more blackish tail ; in these characters huxtoni closely 
resembles G. p. parryii, which, however, is decidedly larger; since 
huxtoni intergrades in characters with ablusus, it may well be given 
subspecific status under the name Citellus parryii huxtoni. 

Specimens examined. — Total number, 274, as follows: 

Alaska: Alaska Peninsula, 110 (Chignik, 24; Cold Bay, 10; Frosty Peak, 17; 
Herendeen Bay, 7 ; " Izembek Bay, 1 ; Katmai, 2 ; Kings Cove, 5 ; Kukak 
Bay, 5 ; Moller Bay, S ; " Morzhovoi Bay, 8 ; Pavlof Mountain, 2 ; Portage 
Bay, 20; Stepovak Bay, 1) ; Anchorage, 1; " Bristol Bay, 1; Cape Prince of 
Wales, 4 ; Eschscholtz Bay, 4 ; Golofnin Bay, 1 ; Jennie Creek, Mount Mc- 
Kinley Park, 1 ; Kakhtul River, 4 ; Kanulik, 3 ; Kavalga Island, 2 ; Kokwok 
River, 1; Lake Aleknagik, 20; Lake Clark, 4; Mount McKinley, 19; Nome, 
Y . 74 75 Nusiiagak, 14 ; Savage River, Mount McKinley Park, 3 ; Pavlof Moun- 
tain, 1; " Swan Lake (Mulchatna-Chulitua Portage), 4; Teller, 1; '' Togiak, 
1 ; Unalaska Island, 55 ; Unimak Island, 11 ; Ushagat Island, 2. 

CITELLUS PARRYII NEBULICOLA Osgood 
Shumagin Geound Squieeel 

Citellus neluUcola Osgood, Biol. Soc. Wash. Proc. 16: 26, Mar. 19, 1903. 

Type. — Collected on Nagai Island, Shumagin Islands, Alaska, 
June 24, 1893, by C. H. Townsend ; female adult, skin and skull, no. 
69145, U. S. Natl. Mus. _ 

Range. — The Shumagin Islands (Nagai, Simeonoff, and Koniuji), 
Alaska (fig. 8). Zonal range: Hudsonian. 

External characters. — Very similar in color to G. p. ablusus, but 
smaller, with shorter tail and hind feet. Compared with G. kodia- 
censis: Size smaller; coloration of upper parts more brownish or 
ochraceous (less grayish) ; under parts darker; tail in summer pel- 
age more tawny (less blackish). 

Granial characters. — Skull similar to that of kodiacensis and 
ablusus but averaging smaller, with relatively longer tooth row; 
closely similar to that of G. p. plesius, but nasals slightly longer, 
narrower at posterior end. and elevated along the median suture. In 
two of the skulls examined the posterior loph on 7n ^ is discontinuous, 
in this character shov/ing approach to kodiacensis. 



'^Amer. Mua. Nat. Hist. 
"•^ Mus. Comp. Zool. 
■^ Colorado Mus. Nat. Hist. 
''^ Carnegie Mus. 



1938] REVISION OF THE GROUND SQUIRRELS IQl 

Color. — SmiiTner pelage: Top of head and face russet or tawny; 
eye ring pinkish buff or buffy white; sides of nose pinkish buff, 
sides of face cinnamon buff, shaded with fuscous; sides of neck, 
and front legs, ochraceous tawny; upper parts snuff browtn or 
verona brown, sprinkled with cinnamon and abundantly flecked 
with creamy white spots; feet cinnamon buff or clay color, the toes 
pinkish buff; tail above, fuscous black, mixed with cinnamon or 
cinnamon buff and edged with pinkish buff; tail beneath, russet or 
mikado brown, tipped with fuscous black; under parts clay color, 
shading to pinkish buff on tliroat. Winter pelage: Upper parts 
similar to the summer pelage but much more whitish, the snuff brown 
hairs more extensively tipped with white, and the shoulders and sides 
pale smoke gray ; tail above, fuscous black, faintly shaded with sayal 
brown and edged with buffy white ; tail beneath, snuff brown or cin- 
namon brown, tipped with black; feet pale pinkish buff; under parts 
white, faintly shaded with pale pinkish buff. 

' Molt. — A specimen taken May 16 is in worn winter pelage, showing 
new summer fur appearing in scattered patches on the head and 
back. 

Measurements. — Average of 3 adult males (measured dry) : Tail vertebrae, 
79.7 (77-S2) ; in 8 adults (4 males, 4 females) the hiud foot (dry) averages 
r)2.1 (50-55.7). Skull: Average of 4 adult females: Greate.'^t length, 52.6 (50.7- 
55.4) ; palatilar length, 20.2 (25.5-27) ; zygomatic breadth, 33.7 (32-35) ; cranial 
breadth, 21.7 (21.1-22.2) ; interorbital breadth, 11.4 (11.1-11.8) ; postorbital 
constriction, 12 (11-13.2) ; length of nasals, 19.4 (18.2-20) ; maxillary tooth row, 
11.5 (11.3-11.7). 

Remarks. — This depauperate insular race shows relationship both 
to ablusus of the mainland and to kodiacensls of Kodiak Island. 
The material at hand is too limited to show clearly its exact rela- 
tionship to the other forms of the species, but since its characters 
overlap those of ahlusus it is assigned a subspecific relationship 
with that race. 

Specimens examined. — Total number, 15, as follows: 

Alaska: Shumagin Islands, 15 (Nagai Island, 10; Koniu.ii Island, 1; Simeonof 
Island, 4). 

CITELLUS PARRYII LYRATUS ILu.l and Gilmorb 

St. Lawkence Island Gkound Squikrel 

(Pis. 24, B; 29, B) 

Citellus lyratus Hall and Gilmore, Calif. Univ. Pubs., Zool. 38: 396, Sept. 17, 1932. 

Type. — Collected at Iviktook Lagoon (about 35 miles northwest 
of Northea.st Cape),^^ St, Lawrence Island, Beriag Sea, Alaska, July 
7, 1931, by Raymond M. Gilmore; male adult, skin and skull, no. 
51172, Mus. Vert. Zool. (orig. no. 1738). 

Range. — St. Lawrence Island, Bering Sea, Alaska (fig. 8). 
Zonal range: Arctic. 

External characters. — Similar to C. p. ahlusus, of the Alaska 
Peninsula, but upper parts paler and more grayish (less brownish) ; 
under parts, sides of nock, legs, and feet paler buff; tail longer and 
more grayish (less tawny) above and paler beneath. Compared 

" Location as defined by R. M. Gilmore, August 1933. 



102 NORTH AMERiaVN FAUNA [No. 56 

with C. p. nebulicola: Size larger; colors paler throughout; tail 
above mainly blackish or grayish rather than tawny. 

Cranial characters. — Skull similar in size and proportions to that 
of dblusus, differing from it in the absence of a prominent sagittal 
crest, the temporal ridges being lyrate in shape, meeting at the 
posterior end only in old age to form a very slight crest ; nasals rela- 
tively broader at posterior end ; posterior loph on m ^ well developed 
and continuous (as in G. huxtoni and ablusus). 

Color. — Summer pelage (July) : Top of head mikado brown; sides 
of face pinkish buff; front legs and sides of neck cinnamon buff; 
general tone of upper parts light brown, heavily spotted with white, 
the individual hairs plumbeous at base, then light pinkish buff, then 
pale fuscous, and tipped with white ; thighs cinnamon buff ; hind feet 
pinkish buff; under parts cinnamon buff, the throat clay color; tail 
above (much worn), grayish white, shaded with dull buffy, the tip 
fuscous or fuscous black; tail beneath, dull, pale russet, edged with 
grayish white and tipped with fuscous black. Worn pointer pelage 
(June 23 and 25) : Upper parts chiefly drab or wood brown; sides 
grayish white; feet pale pinkish buff"; under parts white or dull 
cinnamon buff. 

Molt. — The molt apparently takes place in June or early in July; 
specimens taken June 23 and 25 are in badly worn winter pelage, 
with new hair showing in patches on the head, back, and under 
parts. 

Measurements. — Average of 4 adults (3 males, 1 female) from type locality: 
Total length, 370 (350-381) ; tail vertebrae, 107 (97-114) ; hind foot, 57.2 (54- 
60). Skull: Average of 7 adult males: Greatest length, 57.4 (56.2^58.7); 
palatilar length, 28.7 (28-29.5) ; zygomatic breadth, 36.6 (35.8-37.3) ; cranial 
breadth, 22.9 (22.2-23.3) ; interorbital breadth, 12.8 (12.1-13.9) ; postorbital con- 
striction, 13.8 (13.2-14.1) ; length of nasals, 21.2 (20.5-21.7) ; maxillary tooth 
row, 12 (11.8-12.4). Average of 4 adult females: Greatest length. 54.3 (53- 
56.6) ; palatilar length, 27.4 (27-28) ; zygomatic breadth, 34.2 (33.4-34.9) ; 
cranial breadth, 22 (21.5-22.6) ; interorbital breadth, 11.8 (11.6-12.2) ; post- 
orbital constriction, 13.4 (13-13.9) ; length of nasals, 19.8 (19.2-20.4) ; maxillary 
tooth row, 11.9 (11.5-12.3). 

RcTYiarks. — The St. Lawrence Island ground squirrel seems to be 
most nearly related to the form occurring at Emma Harbor, Siberia,^^ 
which in turn is very close to allusus of the Alaska Peninsula, but 
differs from it in slightly paler coloration and in having a longer tail. 
In skull characters, also, lyratus agrees with the Asiatic species in the 
lyrate shape of the temporal ridges and in tooth characters. C. huoe- 
toni, from Gichiga, Siberia, is decidedly richer (more tawny) in 
color than either lyratus or ahlusus, and has the upper surface of 
the tail more ochraceous, less suffused with black. 

The present form is much more grayish (less tawny) than either 
ahlicsus or huxtoni. It is decidedly smaller, as well as paler colored, 
than paiTyii of the Arctic coast of Alaska. It differs from C. 
kodiacensis in paler colors of the dorsal surface, feet, and tail, 
coarser spotting, and in the crown pattern of the last upper molar. 

Specimens examined. — Total number, 41,^° from St. Lawrence 
Island. 



Tsrptjg ground squirrels of the Chukchi Peninsula (Emma Harbor, Plover Bay, and 
Koliuchin Bay) may prove to be referable to C. stejnegeri of Kamchatl^a, but the single 
specimen (the type) of stejnegeri now available is too young and too much worn to permit 
of satisfactory comparison. 

■'s 15 in Mus. Vert. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS 103 

CITELLUS KODIACENSIS (Aixen) 
KoDiAK Ground Squibbel 

Spermophilus parryi var. kodiacensis Allen, Boston See. Nat. Hist. Proc. 16: 

292, 1874. 
[Spermophilus empeti-a] var. kodiacensis Allen, Monog. North Amer. Rodentia, 

p. 839, 1877. 
[Citellus parryi] kadiacensis Trouessart, Cat. Mamm., Sup., p. 338, 1904. 

Lectotype ^^ — Collected on Kodiak Island, Alaska, June 1868, by 
Ferdinand Bischoff ; female adult, skin and skull, no. ^^^j^, U. S 
Natl. Mus. 

Range. — Kodiak Island (fig. 8). Zonal range: Hudsonian. 

External characters. — Similar to G. parryii ahlusus but dorsal spots 
smaller and more abundant (though sometimes nearly obsolete) ; 
general tone of upper parts in summer pelage more grayish (less 
suffused with ochraceous). 

Cranial characters. — Skull similar to that of ahliisus but molar 
teeth averaging slightly smaller ; m ^ with posterior loph poorly de- 
veloped and often not continuous, but broken by a median sulcus; 
temporal ridges lyrate in shape (as in G. p. lyratus) not uniting pos- 
teriorly in old age to form a prominent crest. 

Golor. — Summer felagc. Head and front of face tawny or pale 
russet, (this color reaching back only to front border of ears) ; sides 
of nose pinkish buff; sides of face and neck cinnamon buff mixed 
with fuscous, shading to ochraceous tawny on throat and base of fore 
legs; upper parts from crown to root of tail mixed fuscous and 
cinnamon buff (the general tone near snuff brown) , extensively tipped 
with buffy white, usually appearing as small irregular spots; shoul- 
ders washed with cinnamon buff; sides of body like back but more 
grayish (less brownish) ; feet clay color or pinkish buff; tail above 
chiefly fuscous black, mixed with tilleul buff and bordered with the 
same; shaded near base with sayal brown; tail beneath, sayal brown 
or mikado brown, much mixed with buff, the tip fuscous black; under 
parts cinnamon buff or pinkish buff. ^Y inter pelage : (April and May 
specimens) : Similar to the summer pelage but tips of hairs on upper 
parts more whitish, especially on shoulders; sides of head, neck, and 
body mainly grayish white, with little buff; feet pinkish buff or 
buffy white ; under parts grayish white, faintly washed with pinkish 
buff. 

Measurements. — Average of 10 adult males from Kodiak Island : Total length, 
358.2 (332-400) ; tail vertebrae, 96.5 (81-112) ; hind foot, 56.4 (52-60). Aver- 
age of 10 adult females from same locality : Total length, 353.2 (333-375) ; tail 
vertebrae, 96.4 (77-104) ; hind foot, 54.7 (51-58). Skull: Average of 10 adult 
males from Kodiak Island: Greatest length, 56.2 (55-57.8); palatilar length, 
28 (27-29) ; zygomatic breadth, 36.8 (35.7-37.6) ; cranial breadth, 23.3 (22.9-24) ; 
interorbital breadth, 12.3 (11.8-13.6) ; postorbital constriction, 12.5 (11.4-14.2) ; 
length of nasals, 21 (19.6-21.9) ; maxillary tooth row, 11.7 (11.2-12.7). Aver- 
age of 10 adult females from same locality: Greatest length, 54.4 (51.8-55.7) ; 
palatilar length, 27.2 (25.5-28) ; zygomatic breadth, 35.5 (34.5-36.8) ; cranial 
breadth, 22.6 (21.7-23.2) ; interorbital breadth, 12 (11.5-12.5) ; postorbital 
constriction, 12.5 (11.5-13.7) ; length of nasals, 20.5 (18.5-21.3) ; maxillary 
tooth row, 11.4 (10.3-12). 



*> No type was designated : this specimen is tlie only one of tiiose listed by Allen in 
liis monograpli (1877, p. 848), now remaining in tiie National Museum collection It is 
liereby designated as a lectotype. 



104 NORTH AMERICAN FAUNA [No. 56 

Remarks. — The Kodiak ground squirrel is closely related to 
ablusus^ inhabiting the nearby mainland, but since it differs in both 
cranial and color characters it is considered a distinct species. Os- 
good states (1903, p. 27), on the authority of a native, that the 
spermophiles on Kodiak Island Trere introduced from North Semidi 
Island; no specimens from the latter island have been seen, but the 
rather pronounced characters of kodiacensis indicate that the species 
probably has occupied Kodiak Island for a long period. 

Specimens examined. — Total number, 45, from Kodiak Island. 

CITELLUS OSGOODI (Merbiam) 

Yukon Vaixkt Ground Squtreel 

(Pis. 24, C; 29, 0) 

Spermophilus osgoodi Merriam, Wash. Acad. Sci. Proc. 2 : 18, Mar. 14, 1900. 
[Citellus] osgoodi Osgood, Biol. Soc. Wash. Proc. 16: 27, 1903. 

7'2/;?e.— Collected at Fort Yukon, Alaska. April 29, 1877, by L. M. 
Turner; male adult, skin and skull; no. iHM; U. S. Natl. Mus. (orig. 
no. 1635). 

Range. — Tlie Yukon Valley, from a point about 25 miles above 
Circle to the Yukon Flats, west of Fort Yukon and possibly to the 
mouth of the Tanana (Osgood, 1900, p. 31) (fig. 8). Zonal range: 
Hudsonian. 

External characters. — Similar to C. pann/ii parry ii but tail longer; 
coloration darker (more reddish) and dorsal spots smaller; feet 
darker. 

Cranial charaxiters. — Slmll closely similar to that of parryii ; audi- 
tal bullae averaging slightly smaller and less inflated. 

Color. — Summer pelage (July) : Entire top of head (nose to occi- 
put) chestnut or bay; sides of nose tawny or ochraceous tawny; sides 
of head, neck, and shoulders hazel or chestnut, sometimes washed 
with ochraceous buff and streaked with blackish; ears ochraceous 
tawny on both surfaces; dorsum mars brown, more or less overlaid 
with pinkish buff, and thickly flecked with spots of buffy white; 
anterior sides hazel; posterior sides like back but more washed 
with buffy ; legs and feet hazel ; under parts hazel or amber brown ; 
tail above, black, more or less overlaid and edged with cinnamon 
buff or tilleul buff; tail beneath, mikado brown, shaded with 
cinnamon buff and broadly tipped with black. Winter pelage (Octo- 
ber-April) : Head as in summer; sides of nose and cheeks cinnamon 
buff or ochraceous buff; nape washed with cinnamon buff or tawny; 
shoulders and fore back extensively overlaid with pale smoke gray 
and sides heavily washed with same; legs and feet tawny; under 
parts tawny or ochraceous tawny, sometimes irregularly shaded with 
cinnamon buff and buffy white; tail hazel beneath. Melanisti^ 
phase : About 20 percent oi the specimens examined are in this phase ; 
most of them are solid blackish brown, more or less sprinkled with 
buffy grayish hairs and with patches of bay on the nose ; several are 
pure black on the entire body, with a few brownish hairs at the tip 
of the tail ; one young specimen is sprinkled with grayish and buffy 
spots on a blackish ground, the nose and feet washed with brownish. 

Molt. — The spring molt begins in late June ; specimens taken near 
Circle June 27-30 show new pelage covering most of the under parts 



1938] REVISION OF THE GROUND SQUIRRELS 105 

and appearing on the head, shoulders, and front legs; others taken 
the same dates are in complete siinmier pelage. A specimen from 
Fort Yukon taken October 15, 1885, was apparently acquiring winter 
pelage, but the method of molting is not clearly shown. 

Measurements. — Average of 10 adult males from near Circle, Alaska : Total 
length, 456.4 (437-475) ; tail vertebrae, 141.7 (131-153) ; hind foot, 62.7 (61-65). 
Average of 10 adult females from same locality: 433 (420-462) ; 136 (126-147) ; 
60.3 (57-63). Skull: Average of 10 adult males from Circle, Alaska: Greatest 
length, 63.1 (60.2-65.S) ; palatilar length, 32.4 (31-34) ; zygomatic breadth, 41.5 
(38.6-44.3) ; cranial breadth, 24.5 (24-25.5) ; interorbital breadth, 14 (12.7-15) ; 
postorbital constriction, 13.4 (12.5-14.8) ; length of nasals, 24 (23-25) ; maxillary 
tooth row, 14 (13.3-14.6). Average of 10 adult females from same localitv : 
Greatest length, 60.1 (58-61.8) ; palatilar length, 29.9 (28-31) ; zygomatic 
breadth, 39.3 (37.4-42) ; cranial breadth, 24 (23.3-25.1) ; interorbital breadth, 
13 (12.3-14) ; postorbital constriction, 13.6 (13-14.4) ; length of nasals, 22.6 
(21.8-23.4) ; maxillary tooth row, 13.9 (13.4^-15). 

Weight of males, 1^ to 2^ pounds (average about 1% pounds) ; of females, 
114 to 1% pounds (average about iy2 pounds) (Osgood. 1909, p. 23). 

Remarks. — The Yukon Valley ground squirrel is the largest known 
member of the farinjii group; in cranial measurements and size of 
hind feet it averages about the same as parryii but exceeds it in length 
of tail. It has a very restricted range along the Yukon River and 
although closely related to parryii apparently does not intergrade 
with it. O. J. Murie, in ascending the Porcupine, saw no squirrels 
until near the mouth of Coleen River; specimens taken there and at 
Salmon Trout River and Rampart House are nearly typical parryii^ 
showing no approach to osgoodi. The lower limit of the species in 
the Yukon Valley is not definitely known, but the upper limit has 
been determined by Osgood as a point about 25 miles above Circle. 
No ground squirrels of any kind occur along the Yukon above that 
point until near the mouth of Pelly River, where the much smaller 
form, C. p. plesiu^s., finds its lower limit. 

Although specimens of this fine squirrel have been in the National 
Museum collection since 18G1, when Kennicott collected a consider- 
able series, they were not recognized as distinct from parryii until 
1900, when Merriam, after Osgood had recognized it in the field, de- 
scribed the species as new. 

Specimens examined. — Total number, 62, as follows : 

Alaska: Yukon River, 62 (Circle, 1; Fort Yukon, 3; mouth of Porcupine River, 
1 ; ^'^ 10 miles above Hess Creek, 1 ; 20 miles above Circle, 55 ; Yukon Flats, 1 ) . 



** Mus. Comp. Zool. 



106 NORTH AMERICAN FAUNA [No. 56 

Subgenus ICTIDOMYS Allen 

[Characters and synonymy on p. 41] 

Key to Species and Subspecies 

c\ Dorsal area striped. 

6\ Larger ; hind foot more tlian 36 mm tridecemlineatus (p. 107) 

&^ Smaller ; hind foot less than 36 mm. 
c\ Dark stripes distinctly reddish (russet or mars brown), texensis (p. 110) 
c^. Dark stripes not distinctly reddish. 
d\ Colors paler (dark stripes snuff brown, walnut brown, or 
cinnamon brown). 

e\ Larger (skull length more than 37 mm) arenicola (p. Ill) 

e^. Smaller (skull length less than 37 mm) parvus (p. 117) 

d^ Colors darker (dark stripes chestnut brown, mummy 
brown, or sepia). 

e\ Larger (skull length more than 37.5 mm) palUdus (p. 112) 

e'. Smaller (skull length less than 37.5 mm). 

f. Dark stripes mummy brown alleni (p. 114) 

f. Dark stripes chestnut brown. 

f/\ Under side of tail russet nwnticola (p. 116) 

g^. Under side of tail chestnut brown liollisteri (p. 115) 

a'. Dorsal area spotted. 
6\ Dorsal spots in linear series. 

c\ Larger ; skull length more than 45 mm mexicanus (p. 119) 

cf. Smaller; skull length less than 45 mm parvidens (p. 121) 

b\ Dorsal spots not in linear series. 

c^. Dorsal spots and under parts buffy perotensis (p. 132) 

c^ Dorsal spots and imder parts white. 
d\ Smaller (skull length less than 36.5 mm). 

e\ Dorsal spots distinct pratensis (p. 128) 

er. Dorsal spots not distinct crypt ospilotus (p. 130) 

d^ Larger (skull length more than 36.5 mm). 
e^. Dorsal spots indistinct or obsolete. 

f. Larger (skull length 39-42.5) major (p. 126) 

f. Smaller (skull length 37.7-39.9) ohsoletus (p. 130) 

e'. Dorsal spots distinct. 

f. Dorsal spots smaller (habitat central Mexico). 

g^. Darker spllosoma (p. 122) 

g-. Paler pallescens (p. 124) 

f. Dorsal si)Ots larger (habitat United States and 
northern Mexico). 

f/\ Smaller (skull length less than 38 mm) canescens (p. 125) 

g\ Larger (skull length more than 38 mm). 

h^. Audital bullae larger major (p. 126) 

7i^. Audital bullae smaller annectens (p. 128) 

CITELLUS TRIDECEMLINEATUS GROUP 
CITELLUS TRIDECEMLINEATUS (Mitchill) 

[SynonjTuy under subspecies] 

Specific characters. — Size small to medium ; hind foot, 28-41 Trmn ; 
tail, 60-108; skull _ length, 34-45.8. Skull relatively long, narrow, 
and weakly built (in comparison with C. toionsendii mollis or C. w. 
washingtoni), the brain case usually longer than broad; interorbital 
region relatively long, the supraorbital margins only slightly ele- 
vated; rostrum long and tapering gradually; zygomata rather stout, 
but not widely expanded ; molarif orm tooth rows slightly convergent 
posteriorly; audital bullae moderately inflated, the external meatus 
tube short. 

Color. — Upper parts marked with a series of alternating light and 
dark longitudinal stripes; the dark stripes are usually five in num- 
ber, brownish or blackish in color and extending down the median 



1938] REVISION OF THE GROUND SQUIRRELS X07 

line of each is a series of squarish white or buffy white spots ; alter- 
nating with the dark stripes are about six narrower whitish stripes ; 
on the sides are several additional, more or less indefinite, stripes 
and spots ; in some races, some of the light dorsal stripes are broken 
into spots. 

CITELLUS TRIDECEMLINEATUS TRIDECEMLINEATUS (Mitchill) 

Thibteen-lined Ground Sqxjireei. 

Sciurus tridecem-lmeatus MitchiU, Medical Repository (n. s.) 6 (21) : 248. 

1821. 
Arctomys hoodii Sabine, Linn. Soc. London. Trans. 13: 590, 1822 (Carlton 

House, Saskatchewan). 
Arctomys tridecemlineata Harlan, Fauna Amer., p. 164, 1825. 
Spermophihis tridecemlineatus Audubon and Bachman, Quad. North Amer. 1: 

294, 1849. 
[Citellus] tridecimlineatus Trouessart, Cat. Mamm., Sup., p. 341, 1904. 

. Type. — None designated. "Brought by Professor Douglas, of the 
United States Military Academy, from the region bordering the 
sources of the river Mississippi, in November 1820" (Mitchill, 1. c). 
Type locality fixed in "central Minnesota" by J. A. Allen (1895b, 
p. 338). 

Range. — Southern parts of Alberta, Saskatchewan, and Manitoba ; 
northern Montana; eastern parts of North Dakota, South Dakota, 
and Nebraska ; northeastern Kansas ; northern Missouri ; all of Iowa ; 
most of Minnesota and Wisconsin; Lower Peninsula of Michigan; 
northern parts of Illinois and Indiana; and southwestern Ohio. 
North to Athabaska Landing, Alberta; east to Fairfield County, 
Ohio; south to central Kansas; west to Red Deer, Alberta, and St. 
Mary Lake, Mont. (fig. 9). Zonal range: Transition and Upper 
Austral. 

External characters. — Size large ; coloration dark ; all light stripes 
continuous, not broken into spots; larger than C. t. texensis and 
averaging more blackish (less reddish). Occasional specimens in 
winter pelage are almost as reddish as texensis^ but always larger. 

Cranial characters. — Skull large (for the species) ; somewhat sim- 
ilar to that of G. tvashingtoni washingtoni but differing in the char- 
acters of the subgenus; narrower brain case; longer rostrum; 
zygomata less spreading; postorbital processes shorter and slenderer; 
anterior premolar relatively smaller; upper incisors shorter and 
stouter. 

Color. — Swnmer pelage (July-September) : Sides of nose cin- 
namon buff; eye ring pinkish buff; cheeks mixed fuscous and cin- 
namon buff; ear rim and sides of neck cinnamon or ochraceous 
tawny; dark dorsal stripes dark fuscous or fuscous black, the five 
median ones each with a row of squarish or rectangular buffy white 
spots down the center: light dorsal stripes buffy white; front legs 
and feet cinnamon buff; hind legs mikado brown or russet, the feet 
cinnamon buff; tail above, fuscous black, mixed with sayal brown 
and bordered with pinkish buff; tail beneath, russet or mikado 
brown at base, shading to ochraceous buff or cinnamon buff toward 
tip, more or less mixed, especially near tip, with fuscous black; 
lower sides cinnamon buff, shading to pinkish buff on throat and 
belly; chin creamy white. Winter pelage (April and May) : Similar 
to the summer pelage but dark dorsal stripes mars brown or chest- 



108 



NORTH AMERICAN FAUNA 



[No. 56 



nut brown, and light dorsal stripes creamy white rather than buffy 
white. 

Measurements. — Average of 10 adult males from Fort Snelling and Elk 
River, Minn.: Total length, 284.9 (274-297); tail vertebrae, 104.7 (90-132); 
liind foot, 39.8 (38-41). Average of 10 adult females from Minnesota and 
Wisconsin: Total length, 267.9 (239-285) ; tail vertebrae, 93.6 (80-103) ; hind 
foot, 37.3 (35-40). Skull: Average of 10 adults from Elk River and Fort 
Snelling, Minn.: Greatest length, 44 (43.2-45.8) ; palatilar length, 20.5 (20-21) ; 




Figure 9. — Distribution of the subspecies of Citellus tridecemlineatus: 1, C. t. tridecemli- 
neatus; 2, C t. pallidus ; 3, G. t texensis; 4, C. t. arenicola; 5, C. t. alleni: 6, C. t. 
parvus; 7, C. t. hollisteri; 8, 0. t. monticola. 

zygomatic breadth, 25.1 (24.4-26.4) ; cranial breadth, 17.6 (17.3-18) ; inter- 
orbital breadth, 8.1 (7.7-9) ; postorbital constriction, 11 (10.2-11.4) ; length 
of nasals, 15.3 (14.3-16.8) ; maxillary tooth row, 7.9 (7.6-S.4). Average of 
8 adult females from same localities: Greatest length, 42.7 (41.2-44.2) ; 
palatilar length, 19.7 (18.5-21) ; zygomatic breadth, 24.3 (23-25.5) ; cranial 
breadth, 17.3 (16.3-18.1) ; interorbital breadth, 8.3 (7.3-9.1) ; postorbital con- 
striction, 11.1 (10.5-11.8) ; length of nasals, 14.9 (14.2-15.6) ; maxillary tooth 
row, 7.8 (7.4-8.2). 

V/eiffht. — Wade (1930, p. 170) gives the weights of four males as ranging 
from 170-243 g ; of four females, from 14rt-211 g. 



1938] REVISION OF THE GROUND SQUIRRELS 109 

Remarks. — The typical race of the striped ground squirrel has 
an extensive range in the upper Mississippi Valley and the northern 
plains and is an abundant animal over most of its range. Consid- 
erable individual and seasonal variation is shown in nearly every 
series of this race, specimens taken in midsummer being the darkest 
and those taken in late spring decidedly paler and more tawny (less 
brownish). Specimens from near the northern limits of its range 
(Edmonton, Alberta) are not appreciably different from typical 
specimens, but those from northwestern Montana (St. Mary Lake 
and Choteau) are somewhat paler, thus showing approach to C. t. 
■pallidus. Intergradation with the latter is shown also, by numerous 
specimens from central North Dakota, South Dakota, Nebraska, and 
Kansas. A large series from Knoxville, Iowa, shows approach to 
texeTisis in slightly smaller size and in the reddish tone of the under 
side of the tail. The under parts are more strongly buffy than in 
either tridecemlineatus or texensis. A small series from Onaga, 
- Kans., is typical. The large series examined from Leavenworth and 
Douglas Counties, Kans., is intermediate between tridecemlineatus 
and texensis.^ but a little nearer to the former; the one summer speci- 
men is clearly tridecemlineatus; the skulls are intermediate in size. 
Specimens examined. — Total number, 44.5, as follows: 

Alberta: Chief Mountain Lake, 1; Red Deer, 3; South Edmonton, 5; Sturgeon 
River (25 miles north of Eclmontoi!). 1. 

Illinois: Chicago, 15;" Kansas, 1; Riverdale (Cook County), 1;" Warsaw, 1; 
Waukegan, 1;" Wheatland To'.vnshiri (Will County). 1."' 

Indiana: La Fayette (8 miles east), 1; Lake Village (Newton County), 1;" 
Logansport, 1;^ Montezuma (Parke County). I:*" Notre Dame. 2;*^ Pine 
Station (Lake County), 1; Roseland (St. Joseph County), 1;" Ro.val Cen- 
ter, 2; South Bend, 1;" Wahash Township (Tippecanoe County), 1. 

Iowa: Ames, 1;** Burlington, 22; Knoxville, 16; Luxemhurg, 1.** 

Kansas: Douglas County, 12;** Fort Leavenworth, 1; Fort Riley, 1; Lawrence, 
8 ;" *° Leavenworth, 5 f Onaga, 5. 

Manitoba: Carherry. 34; Red River Settlement, 1. 

Michigan: Alma, 2;'' Ann Arbor, 13;*" Birchwood Beach (Berrien County), 1;" 
Boyne Falls (Charlevoix County), 1;'^ Boyne Valley (Charlevoix County), 
1;" Byron (Shiawassee County), 2;*^ Chelsea, 1:*^ Douglas Lake (Cheboy- 
gan County), 1;** Harbert (Berrien County), 1 ;" Higgins Lake (Roscom- 
mon County), 1;" Le Roy (Osceola County). 2;^ Lucerne (Oscoda County), 
1 f^ Manchester, 1 ;" Montmorency County, 2 ;*^ Otsego County, 1 ;" Portage 
Lake (Washtenaw County), 3;*^'" Warren Preserve (Berrien County), 2;** 
Waterloo (Jackson County). 1.** 

Minnesota: Brown Valley, 3; Elk River, 21; Fort Snelling (Hennepin County), 
4;" Geneva Lake (Freeborn County), 1: Germantown (Marshall County), 
1; Goodhue, 3;" Hutchinson, 1; Ortonville, 2; Princeton (Benton County), 
1; Waseca County, 1.*^ 

Montana: Bear Paw Mountains (20 miles southeast of Port Assiniboine) , 1; 
Blackfoot Agency (Glacier County), 1; Choteau. 1; Johnson Lake (Roose- 
velt County), 1; St. Mary Lake. 3: St. Mary River (15 miles below St. 
Mary Lake), 1: Zortman (Phillips County), 1. 

Nebraska: Broken Bow, 1;" Columbus, 4; Glen (Sioux County), 1;** North 
Platte, 2;»* Verdigris, 1. 

North Dakota: Bismarck, 2; Bottineau, 1; Braddock, 2-^ Buford (Williams 
County). 3; Casselton, 1; Crosby. 1; Dawson (Kidder County), 1: Devils 
Lake, 1 ;'=' Drayton, 1 ; Ellendale, 1 ; Fairmount, 7 : Fargo, 3 ; Fort Berthold 
(McLean County), 1; Fort Buford (Williams County), 3; Grand Forks. 4; 
Grafton, 3; Grinnell (Williams County), 1; Hankinson, 2; Harwood (Cass 
County), 1; Lidgerwood, 1; Ludden (Dickey County), 2; Minot, 4;"^ Oakes, 
5; Old Fort Union (near Buford), 4; Pembina. 9; Portland, 1; Stark- 
weather, 2; Steele, 8;"= Streeter, 1; Stump Lake, 2; Towner, 3; Turtle 
Creek (near Washburn), 3; Valley City. 3; Walhalla, 1; Washburn, 1; 
Yellowstone River (mouth), 2; Zeeland, 1. 

See footnotes on page 110. 



210 NORTH AMERICAN FAUNA iNo. 56 

Ohio: Bainbridge (Ross County), 9;^' Circleville, 1;*" Lancaster, 6. 

Saskatchewan : Grenfell, 1 ; Indian Head, 3 ; Livelong, 2 ; "" Prince Albert, 2 ; ^ 
Wingard, 4. 

South Dakota: Plandreau, 2; Fort Randall (Gregory County), 1; Mitchell, 2; 
Pierre, 2 ; Lake Traverse, 5 ; Vermillion, 1 ; "^ White Lake (Avirora County), 1. 

Wisconsin: Bay Settlement (Brown County), 3;** Beaver Dam, 14;°^ Ben- 
derville (Brown County), 1;^ Bussyville ( = Sumner, Jefferson County), 1; 
Camp Douglas (Juneau County), 1; Clark County, 2;^^ Danbury (Burnett 
County), 2; Delavan, 1; Devils Lake (Sauk County), i; Endeavor, 2; 
Friendship, 2; Green Lake, 4; Herbster (Bayfield County), 2; Holcombe 
(Chippewa County), 2; Kelly Lake (Oconto County), 1; La Crosse, 2; Long 
Lake (Washburn County), 1; Mather (Juneau County), 2; Namakagon 
Lake (Bayfield County), 1; Nashotah (Waukesha County), 2; Orienta 
(Bayfield County), 2; Prescott, 1; Racine, 7; Rib Hill (Marathon County), 
6; Solon Springs, 2; Stevens Point, 1; Three Falls (15 miles west of 
Crivitz, Marinette County), 2f* Wauzeka (Crawford County), 1. 

CITELLUS TRIDBCEMLINEATUS TEXENSIS (Mebriam) 

Texas Stetped Ground Squierel , 

Sperniophilus tridecemlineatus texensis Merriam, Biol. Soc. Wash. Proc. 12 : 71, 

Mar. 24, 1898. 
Sperrnophilus (Ictldomt/s) tridecemlineatus dadius Bangs, New England Zool. 

Club Proc. 1: 1, 1899 (Stotesbury, Mo.). 
[Citellus tridecemlineatus'] texensis Trouessart, Cat. Mamm., Sup., p. 342, 1904. 

Type. — Collected at Gainesville, Tex., April 15, 1886, by George H. 
Ragsdale; male adult, skin and skull, no. 186471, U. S. Natl. Mus. 
(formerly no. f|^, Merriam collection). 

Range. — Prairie region of middle eastern portions of Texas and 
Oklahoma; north to southeastern Kansas (Cairo and Garden Plain) ; 
east to southwestern Missouri (Stotesbury and Golden City) ; south 
to Bee County, Tex. ; west to Vernon, Tex., and Mount Scott, Wichita 
Mountains, Okla. (fig. 9). Zonal range: Lower Austral. 

Extejmal characters. — Similar to C. t. tridecemlineatus but smaller, 
with upper parts and under side of tail paler and more reddish. 

Cranial characters. — Skull similar to that of tridecemlineatus but 
smaller, and relatively broader across brain case and zygomata. 

Color. — Winter pelage (April) : Dark dorsal stripes russet or mars 
brown; light stripes and spots creamy white; eye ring buffy white; 
lower sides and under parts cream color or pinkish buff; fore and 
hind feet pinkish buff or buffy white; tail above, same color at base 
as the back, but more or less overlaid with whitish hairs, and shading 
to cimiamon buff on distal portion, the hairs on sides of tail tilleul 
buff at tips with a subterminal band of fuscous black ; tail beneath, 
russet in center, edged and more or less overlaid with tilleul buff. 
Summer pelage (August) : Dark strikes chestnut brown; light stripes 
buffy white to pale cinnamon buff. 

Measurements. — ^Average of 10 adults (4 males, 6 females) from Texas (Ver- 
non, Wichita Falls, Henrietta, Gainesville) : Total length, 258 (227-267) ; tail 
vertebrae, 92 (80-102); hind foot, 34 (33-36). Slvull: Average of 11 adults 
(4 males, 7 females) from Texas (Gainesville, Vernon, Henrietta, Richmond, 



*2 Univ. Michigan Mus. Zool. 

*3 p. F. Hickie collection. 

^ Univ. of Notre Dame. 

^Kansas Univ. Mi.is. Nat. Hist. 

*" Cornell Univ. Mus. 

®^Amer. Mus. Nat. Hist. 

** Univ. Nebraska. 

89 Cleveland Mus. Nat. Hist. 

0" William T. Shaw collection. 

»i South Dakota State Biol. Survey. 

»= Field Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS m 

Wichita Falls) : Greatest length, 40.4 (39.5-42.1) ; palatilar length, 19 (18.2-20) ; 
zygomatic breadth, 24.2 (23.1-25.8) ; cranial breadth, 17.8 (16.9-18.9) ; inter- 
orbital breadth, 8 (7-8.4) ; postorbital constriction, 11.9 (10.7-12.6) ; length of 
nasals, 14.3 (13.2-15.6) ; maxillary tooth row, 7.5 (7.3-8). 

Remarks. — The Texas ground squirrel is a well-marked form, 
characterized especially by its reddish coloration. Specimens from 
Kiowa and Cairo, Kans., and Alva, Okla,, are paler than typical 
specimens, thus showing apf>roach to G . t. arenicola. A single speci- 
men from Dimmitt, Tex., seems referable here, although on geo- 
graphical grounds it should be within the range of arenicola. 

The series from Stotesbury, Mo., which formed the basis of 
'"'"'badius''' of Bangs is closely similar in color to texensis., winter 
specimens being practically indistinguishable ; summer specimens are 
slightly darker (more blackish) and the skulls are slightly larger. 
The series is thus intermediate between texensis and tridecemlineatiis 
but with too slight characters for recognition by name. 

Specimens examined. — Total number, 72, as follows: 

Kansas : Anderson County, 1 ; " Belle Plaine, 2 ; Columbus, 1 ; °^ Garden Plain, 
1 ; Independence, 2."^ 

Missouri: Golden City, 5; Stotesbury (Vernon County), 12;"* Washburn (Barry 
County), 6. 

Oklahoma: Apache, 1; Arnettville, 1;*° Fort Reno (Canadian County), 2; Law- 
ton, 1; Mount Scott P. O. (Comanche County), 14; Noble, 2; '^ Norman, 2:*' 
Orlando, 3. 

Texas: Cooke County, 1; Gainesville, 2; Henrietta, 3; Richmond, 4; Vernon, 
4; Wichita Falls, 2. 

CITELLUS TRIDECEMLINEATUS ARENICOLA Howell 

Sandhill Stetped Ground Squierkl 

Citellus tridecemlineatus arenicola Howell, Biol. Soc. Wash. Proc. 41: 213, 
Dec. 18, 1928. 

Type. — Collected at Pendennis, Kans., April 22, 1897, by J. Aldeii 
Loring; male adult, skin and skull; no. 87686, U. S. Natl. Mus. (Bio- 
logical Survey collection) (orig. no. 3988). 

Range. — Southwestern Kansas, eastern Colorado, northwestern 
Texas, northwestern Oklahoma, and eastern New Mexico; north to 
Logan County, Colo. ; east to Barber County, Kans. ; south to Lub- 
bock, Tex., and Roswell, N. Mex. ; west to Lincoln County, N. Mex. 
(fig. 9). Zonal range: Upper Sonoran. 

External characters. — Similar to G. t. pallidus., but smaller and 
paler, the dark dorsal stripes snuff brown instead of sepia; similar, 
also, to G. t. texensis., but smaller and much paler. 

Granial characters. — Skull similar to that of pallidus., but aver- 
aging slightly smaller, except in breadth of the cranium; nasals 
shorter. 

Golor. — Winter pelage (April 23) : Dark dorsal stripes snuff 
brown or Front's brown ; light dorsal stripes and spots white, some- 
times faintly washed v/ith pale buff; tail above, cinnamon buff, 
shaded with bister, becoming fuscous or fuscous black on distal end, 
strongly margined with buffy white; tail beneath, tawny on median 
basal portion, shading to cinnamon on distal portion, edged with 
fuscous black and tipped with buffy white; feet, under parts, and 



•* K.insas Univ. Mus. Nat. Hist. 
•*Mus. Comp. Zool. 
•» Field Mus. Nat. Hist. 



2]^2 NORTH AMERICAN FAUNA [No. 56 

sides buffy white. Summer pelage (Lipscomb, Tex., July 8) : Dark 
dorsal stripes cinnamon brown ; light stripes tilleul buff ; under parts 
and sides dull buffy white ; hind feet pinJkish buff ; tail as in wmter 
pelage. 

Measurements. — Average of 8 adults (4 males, 4 females) from type locality: 
Total length, 238 (214-295) ; tail vertebrae, 77.7 (71-83) ; hind foot, 32.2 
(31-34). Skull: Average of 8 adult males (3 from Pendennls, 5 from Morton 
County, Kans.) : Greatest length, 39.1 (38.3^0.3) ; palatilar length, 17.9 (17.5- 
18.5) ; zygomatic breadth, 23.2 (22.6-24.3) ; cranial breadth, 17.2 (16.8-17.6) ; in- 
terorbital breadth, 8.1 (7.4-8.9) ; postorbital constriction, 12 (11.6-12.5) ; length 
of nasals, 13.9 (13.2-14.9) ; maxillary tooth tow, 7.2 (6.8-7.7). Average of 8 
adult females from same localities: Greatest length, 38.1 (37.3-39.7) ; palatilar 
length, 17.7 (17.1-18) ; zygomatic breadth, 22.7 (21.9-23.4) ; cranial breadth, 
17 (16.2-17.8) ; interorbital breadth, 7.6 (7-8.2) ; postorbital constriction, 13.5 
(13-14.4) ; length of nasals, 13.5 (13-14.4) ; maxillary tooth row, 7 (6.7-7.2). 

Remarks. — This race is the palest of all the forms of this species. 
The dorsal stripes are more reddish in tone than in palUdus, m this 
respect showing approach to texensis. Intergradation with pallidus 
occurs in eastern Colorado, northwestern Kansas, and western Ne- 
braska. A large series from Baca County, southeastern Colorado, is 
typical of arenicola in color, but the skulls are like those of paUidus. 

Specimens examined. — Total number, 110, as follows : 

Colorado: Akron, 1 ; '^ Eureka Hill (Cheyenne County), 1; Greeley, 1; Kit 
Carson County, 1;'" Leroy (Logan County), 1; Monon (Baca County), 6;" 
Springfield (Baca County), 8; "' Sterling, 5; Tuttle (Kit Carson County), 1 ; 
Washington County, 2;'"'"MVray, 3;'° Wray (20 miles northwest), 1.'' 

Kansas: Banner (Gove County), 2;"^ Cairo (Pratt County), 1; Clark County, 
1;*" Coolidge (Hamilton County), 1;"* Fowler (Meade County), 2;°^ Grin- 
nell (Gove County), 2 ; ^ Kiowa, 4; Medicine Lodge 1 ; Morton County, 13 ; ^ 
Oaklev, 1; Oanica (Kearney County), 2;"* Pendennis (Lane County), 10; 
Phillipsburg, 1 ; '^^ Scott City, 3 ; Wallace (Wallace County), 1.°* 

New Mexico: Cabra Springs (6 miles north, San Miguel County), 1; Chico 
Springs (Colfax County), 1; Clayton, 1; Folsom, 1; Loveless Lake (10 miles 
northwest of Capitan Mountains, Lincoln County), 1; Preston (Colfax 
County), 1; Roswell, 1; San Jon (Quay County), 5;^ Tucumcari (25 miles 
west), 1. 

Oklahoma: Alva, 4;' Woodward, 3. 

Texas: Dimmitt (20 miles south), 1; Lipscomb, 3; Lubbock, 2; Mobeetie, 1; 
Texliue (20 miles east), 1; Washburn, 6. 

CITELLUS TRIDECEMLINEATUS PALLIDUS (Aixen) 

Palud Striped Geound Squxrbei, 

[SpermopMlus trldecemlineatus] var. pallidus Allen, Monog. North Amer. 

Rodentia, p. 872, 1877. 
[Citellus tridecimlineatus'] palUdus Trouessart, Cat. Mamm., Sup., p. 341, 1904. 
SpermopMlus tridecemlineatus oUvaceus Allen, Amer. Mus. Nat. Hist. Bull. 7: 

337, 1895 (Custer, S. Dak.), 

Type. — None designated; type locality, mouth of the Yellowstone 
River, Mont.* 

Range. — Plains of Montana east of the Rocky Mountains, eastern 
Wyoming, northeastern Colorado, northwestern Kansas, western 



** Univ. Micbigan Mus. Zool. 
^' E. R. Warren collection. 
'8 Kansas Univ. Mus. Nat. Hist. 
«9 Colorado Mus. Nat. Hist. 

* Kansas State Agr. College. 
2 Cleveland Mus. Nat. Hist. 

8 Two in Field IMus. Nat. Hist. 

* Cf . Allen (1895b, p. 338) -wliere the type region is designated as "plains of the Lower 
Yellowstone River." In order to fix the type locality more definitely, specimen number 
16237, U. S. National Museum, taken Aug. 18, 1857, at the mouth of the Yellowstone, 
by F. V. Hayden, is here selected as a lectotype. 



1938] REVISION OF THE GROUND SQUIRRELS 1X3 

parts of Nebraska and South Dakota, and southwestern North 
Dakota; north to the Missouri River in Montana, east to the Mis- 
souri in North Dakota, and to about the 100th meridian in Nebraska 
and Kansas; south to Ellis and Trego Counties, Kans., and Colorado 
Springs, Colo. ; west to Casper and Laramie, Wyo., and to Canadian 
Creek (North Park) and Como (South Park), Colo. (fig. 9). 
Zonal range : Upper Sonoran and Transition. 

External characters. — Similar to G. t. tridecemlineatus but smaller 
and paler. 

Cranial characters. — Skull similar to that of tridecemlineatus, but 
decidedly smaller and with relatively broader rostrum and brain 
case. 

Color. — Summer pelage (August and September) : Dark dorsal 
stripes sepia ; light stripes and spots grayish white or ca,rtridge buff ; 
front and sides of face pinkish buff, washed with pinkish cinnamon 
on nose; front feet pinkish buff; hind feet cartridge buff, the legs 
.cinnamon buff or washed vrith cinnamon or clay color; tail above and 
beneath, cinnamon buff, mixed with fuscous black and overlaid with 
pinkish buff' ; under parts and lower sides cartridge buff, shaded with 
pinkish buff. Winter pelage (May 21) : Very similar to the summer 
pelage, but light dorsal stripes and spots more whitish (less buffy) ; 
sides of face, neck, and body pinkish buff. 

Measurements. — Average of 10 adult males from eastern Montana: Total 
length, 244.2 (214-255); tail vertebrae, 80.7 (60-91); hind foot, 32.9 (31-35). 
Average of 10 adult females from same section: Total length, 232.5 (220-252) ; 
tail vertebrae, 82.2 (76-91) ; hind foot, 32.3 (31-35). Skull: Average of 7 adult 
males from eastern Montana: Greatest length, 39.5 (38-42.1) ; palatilar length, 
18.5 (17.5-19.5) ; zygomatic breadth, 23.2 (22.3^24.6) ; cranial breadth, 17.1 
(10.6-18.3) ; interorbital breadth, 7.6 (7.2-8.4) ; postorbital constriction, 11 
(10-11.7) ; length of nasals, 14.8 (14-15.4) ; maxillary tooth row, 7 (6.7-7.3). 
Average of 10 adult female.s from same section : Greatest length, 38.8 (30.4- 
41.3) ; palatilar length, 18.2 (17-19.8) ; zygomatic breadth, 23.1 (21.9-24.7) ; 
cranial breadth, 16.8 (15.8-17.9) ; interorbital breadth, 7.3 (6.6-7.8) ; postorbital 
constriction, 10.6 (9.9-11.3) ; length of nasals, 14.3 (13.4-15.7) ; maxillary tooth 
row, 7 (6.5-7.4). 

Remarks. — The pallid ground squirrel is distinctly smaller and 
paler than the typical race, but larger and darker than C. t. parvus 
and C. t. arenicola. It was described from the plains of the lower 
Yellowstone, at the northern edge of its raiige. On the north side of 
the Missouri River, directly opposite the mouth of the Yellowstone, 
the squirrels are darker and are referable to tridecemlineatus. In- 
tergradation with the typical race occurs over a considerable strip of 
country in the central parts of North Dakota. South Dakota, Ne- 
braska, and Kansas. Southward, in eastern Colorado and north- 
western Kansas, this race intergrades with arenicola. Doubtless it 
intergrades also with C. t. alleni in the foothills of the Bighorn 
Mountains, but no specimens are available from that section. Four 
specimens from Casper, Wyo., are typical of pallidus in color, but 
the skulls are smaller and more like those of parvus. 

The type series of ''^olivaceus'''' from Custer, S. Dak., has been com- 
pared with a large series of typical pallidus and is found to agree 
closely with it. 



154970—38 8 



11/^ ' NORTH AMERICAN FAUNA [No. 56 

Specimens examined. — ^Total number, 314, as follows : 

Colorado: Barr (Adams County), 3;° Boulder, 1; Canadian Creek (Jackson 
County), 5; Colorado Springs, 20;'^ Como (Park County), 5; Deer Trail 
Arapahoe County), 1;^ Denver, 2; Divide (Teller County), 6/ Elbert (6 
miles south), 1;' Elbert County (between Mattison and Resolis), 1;" Elk- 
horn (Larimer County), 1; Fort Collins, 1; Golden, 2; Horsetail Creek 
(Weld County), 5;^ Loveland, 22; Manitou, 1;'^ Pav^nee Buttes (Weld 
County), 2; Puma City (Park County), 1;* Simla (12 miles east), 1;^ 
Tarryall Creek (Park County), 1;^ Valmont (Boulder County), 1. 

Kansas: Atwood (10 miles east and 27 miles west) , 2 ; * Colby, 1 ; Ellis, 1 ; Hays, 
1; Logan County, 3*; North Solomon River (Graham County), 1; Solomon 
River (Graham County), 1; Trego County, 10; Woodston (Rooks 
County), 3.' 

Montana: Albion (Carter County), 1; Baker (10 miles north, 4; Billings, 1; 
Broadus (10 miles northeast), 1; Capitol (Carter County), 2; Cohagen 
(16 miles southeast, Garfield County), 2; Crow Agency (Bighorn County), 
5; Fort Custer (Bighorn County), 2; Intake (Dawson County), ?.; Little 
Bighorn River (2 miles north of Wyoming border), 1; Little Dry Creek 
(Garfield County), 1; Medicine Rocks (Carter County), 3; Melstone (Mus- 
selshell County), 1; Pilgrim Creek (10 miles east of Broadus), 1; Piney 
Buttes, 1; Powderville (Powder River County), 6; Pryor Mountains (Car- 
bon County), 1; Roy (20 miles northeast, Fergus County), 1; Terry, 1; 
Tilyou Ranch (26 miles above mouth of Yellowstone River), 3; Wibaux 
(17 miles south and 17 miles west), 11. 

Nebraska: Antioch (Sheridan County), 2;' Beaver City, 1; Birdwood Creek 
(Lincoln County), p.; Blue River (near head, Hamilton County), 1; Calla- 
way, 1; Cody (Cherry County), 1; Eustis (Frontier County), 1; Gavin 
Custer County), 1 ; '^ Gothenberg, 1; Grand Island, 1;* Hackberry Lake 
(Cherry County), 2;^ Homerville (Gosper County), 1; Kelso (Hooker 
County), 2;' Kennedy (Cherry County), 8; Myrtle (Lincoln County), 1; 
Niobrara River (Cherry and Sheridan Counties), 2; North Platte, 6; O'Fal- 
lons Bluff (Lincoln County), 1; Sidney, 1; Valentine, 21. 

North Dakota: Fort Clark (Oliver County), 4; Glen UUin (Morton County), 6; 
Heart River (at head), 1; Mandan, 2; Mikkelson (Billings County), 1; 
Oakdale (Dunn County), 2; Sentinel Butte (Valley County), 2. 

South Dakota: Ai-dmore (Fall River County), 1; Buffalo Gap (Custer County), 
2; Buffalo Valley (Stanley County), I; Bull Springs (near Custer), 10;" 
Custer, 21:'" Diamond S Ranch (near Rapid City), 1;* Elk Mountain 
(Custer County), 1; Minichaduza River (Todd County), 1; Pactola (Pen- 
nington County), 1; Pine Ridge Agency (Shannon County), 1; Spring Creek 
(Custer County), 1." 

Wyoming: Bear Lodge Mountains (Crook County), 1; Casper, 4; Cassa (Platte 
County), 1; Cheyenne, 13; Chugwater (Platte County), 3;* Douglas, 3; 
Fort Laramie, 1; Fort Russell (Laramie County), 1; Islay (Laramie 
County), 1; Medicine Bow Mountains, 1; Moorcroft (Crook County), 6; 
Newcastle (and 25 miles southwest), 3; Pine Bluffs (Laramie County), 3; 
Spoon Butte (Goshen County), J; Sundance, 1. 

CITELLUS TRIDECEMLINEATUS ALLENI (Mebeiam) 

Bighorn Stetpei) Gkound Sqxjibeel 

Spermophilus tridecemlineatus alleni Merriam, Biol. Soc. Wash. Proc. 12: 71, 

Mar. 24, 1898. 
[Citellus tridecimlineatus'] alleni Trouessart, Cat. Mamm., Sup., p. 341, 1904. 

Type. — Collected near head of Canyon Creek, west slope of Big- 
horn Mountains, Wyo. (altitude 8,000 feet), September 11, 1893, by 
Vernon Bailey; male adult, skin and skull, no. 56050, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 4383). 



^ Colorado Mus. Nat. Hist. 
' E. R. Warren collection. 
'' Univ. Michigan Mus. Zool. 
^ Kansas Univ. Mus. Nat. Hist. 
•Cleveland Mus. Nat. Hist. 
«Amer. Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 115 

Range. — The Bighorn Mountains and Bighorn Basin, Wyo. ; south 
to head of Red Canyon, near Miners Delight, Fremont County, and 
west to New Fork of Green River (fig, 9). Reported also from 
Franks Butte, near head of Sage Creek, Park County, Wyo. Zonal 
range: Transition. 

External characters — Similar in coloration to C. t. tridecemline- 
atus but slightly paler and much smaller; size of G. t. 'parvus but 
much darker. 

Cranial characters. — Skull smaller than that of tridecemlineatus 
or C. t. pallidus; similar to that of parvus but relatively longer, with 
smaller audital bullae and much longer nasals. 

Color. — Summer pelage (September) : Dark dorsal stripes mummy 
brown ; light spots and stripes grayish white ; nose and front of face 
cinnamon buff ; sides of face pinkish buff, washed with fuscous ; front 
feet pinkish buff; hind feet tilleul buff, the thighs cinnamon buff, 
washed with snuff brown; tail above, like the back at base, shading 
to fuscous black on terminal half, edged with tilleul buff or buffy 
white; tail beneath, cinnamon or pinkish cinnamon, overlaid and 
edged with buffy white and fuscous black; under parts and lower 
sides soiled whitish, washed with pinkish buff. 

Measurements. — Average of 3 adults (1 male, 2 females) from Bighorn Moun- 
tains and Bighorn Basin: Total length, 206.3 (203-211) ; tail vertebrae, 74 (73- 
75) ; hind foot, 31 (30-32). Skull: Average of 3 adults (1 male, 2 females) 
from same localities: Greatest length, 36.4 (35.8-36.8) ; palatilar length, 16.4 
(;16.2-16.5) ; zygomatic breadth, 19.9 (19.5-20.1) ; cranial breadth, 16 (16-16.1) ; 
interorbital breadth, 7.5 (7.1-7.7) ; postorbital constriction, 11.3 (10.8-11.6) ; 
length of nasals, 13.2 (12-14.5) ; maxillary tooth row, 6.6 (6.4-6.8). 

Remarks. — The Bighorn ground squirrel is an inhabitant of moun- 
tains and foothills, and is decidedly darker than the races living on 
the plains. The limits of its range are not well knoAvn. 

Specimens examined. — Total number, 6, as follows: 

Wyoming: Bighorn Basin (head of Kirby Creek, Hot Springs County), 1; Big- 
horn Mountains (west slope, near head of Canyon Creek), 2 ; Miners Delight 
(near head of Twin Creek, Fremont County), 1; New Fork of Green River 
(Lander Road), 2. 

CITELLUS TRIDECEMLINEATUS HOLLISTERI Bailet 

Hor.LisTEB's Striped Ground Sqihrrel 

Citellus tridecemlineatus hoUisteri Bailev, Biol. Soc. Wash. Proc. 26: 131, May 
21, 1913. 

Type. — Collected in Elk Valley, Mescalero Indian Reservation, 
Sacramento Mountains, N. Mex. (8,000 feet altitude), September 11, 
1902, by Vernon Bailey; female adult, skin and skull, no. 119025, 
U. S. Natl. Mus. (Biological Survey collection) (orig. no. 7963). 

Range. — Sacramento Mountains, N. Mex., and mountain valleys of 
northeastern New Mexico; western limits of range not known (fig. 
9). Zonal range: Transition. 

External characters. — Similar to C. t. alleni, but dark dorsal stripes 
slightly more reddish and light stripes tinged with buff, the median 
pair of light stripes usually continuous ; hind feet washed with buff. 

Cranial characters. — Skull similar to that of alleni., but with 
heavier and more widely spreading zygomata; larger than that of 
C. t, parvus. 



116 NORTH AMERICAN FAUNA [No. 56 

Color. — Summer 'pelage (September) : Dark dorsal stripes chest- 
nut brown; crown same color mottled with whitish spots; a broad 
whitish or buffy eye ring; front of face tawny olive; sides of nose 
pinkish buff; light dorsal stripes and spots grayish wliite, faintly 
tinged with buff; front legs and feet cinnamon buff; hind legs cin- 
namon; hind feet dull white, washed with buff; tail (above and 
below) chestnut brown at base, becoming black on distal half, over- 
laid with tilleul buff; under parts and sides pinkish buff or pale 
cinnamon buff. 

Measurements. — Average of 5 adult females from type locality: Total length, 
211.2 (200-232) ; tail vertebrae, 71.8 (60-85) ; hind foot, 30.7 (30-32). Skull: 
Average of 4 adult females: Greatest length, 36.1 (35-37.4) ; palatUar length, 
16.7 (16-17) ; zygomatic breadth, 20.7 (19.3-21.7) ; cranial breadth, 15.9 (15.3- 
16.4) : interorbital breadth, 7.3 (6.5-7.8) ; postorbital constriction, 11.6 (11.2- 
12.2) ; length of nasals, 13.2 (12.8-13.8) ; maxiUary tooth row, 6 (5.9-6.2). 

Bemarks. — This race seems to have a discontinuous range; de- 
scribed from the Sacramento Mountains, southern New Mexico, it 
proves to occupy, also, the mountain valleys in the northeastern part 
of the State north nearly or quite to the Colorado line, where it inter- 
grades with 0. t. arenicola of the plains region to the eastward. The 
specimens from this region have the dark dorsal stripes more brown- 
ish (less reddish) than in the typical series. Further collecting in 
central New Mexico may result in partly connecting this range. 
Although very similar in external appearance to alleni,, of the Big- 
horn Mountains, Wyo., the range of holUsten is separated from the 
range of that form by a wide area in western Colorado mainly 
occupied by parvus. 

Bailey (1931, p. 119) has referred the specimens from Moreno 
Valley to alleni, on the strength of their close resemblance to that 
race in color; however, the skulls of these New Mexico specimens 
agree closely with those of hollisteri and differ from those of alleni 
in heavier build and more widely spreading zygomata. It seems 
preferable, therefore, by reason of their proximity to the type region 
of hollisteH., to refer them to that race. 

Specimens exannin£d. — Total number, 17, as follows : 

New Mexico: Cimarron (35 miles northwest), 1; Las Vegas (12 miles north), 
1; Maxwell, 1;" Mescalero Reservation (Elk VaUey, Sacramento Moun- 
tains), 7; Mora (10 miles south), 2; Moreno Valley (Colfax County), 5. 

CITELLUS TRIDECEMLINEATUS MONTIOOLA HowEiJ. 

Aeizona Stkiped Geounb Squieeel 

Citellus tridecemlineatus mcnticola Howell, Biol. Soc. Wash. Proc. 41: 214, 
Dec. 18, 1928. 

Type. — Collected at Marsh Lake, Wliite Mountains, Ariz. (9,000 
feet altitude), June 15, 1915, by Edward A. Goldman; male adult, 
skin and skull, no. 209255, U. S. Natl. Mus. (Biological Survey col- 
lection) (orig. no. 22616). 

Range. — Known only from the type locality (fig. 9). Zonal 
range: Transition. 

External characters. — Similar to C. t. alleni but upper parts 
slightly and under side of tail decidedly more reddish. Similar to 



"Reading (Pennsylvania) Public Mus, 



1938] REVISION OF THE GROUND SQUIRRELS WJ 

C. t. parvus^ but larger ; coloration of upper parts and under side of 
tail darker; under parts more buffy (less whitish). Compared with 
G. t. hollisteri: Upper parts paler, the light dorsal stripes more 
whitish (less buffy) ; under side of tail more reddish. 

Cranial characters. — Skull similar to that of hollisteri^ but nasals 
shorter; decidedly larger than that of 2)arvus^ but with relatively 
smaller molars; similar to that of alleni but with heavier and more 
spreading zygomata. 

Color. — Summer pelage (June 15) : Dark dorsal stripes chestnut 
brown; light stripes and spots, and eye ring, creamy white; front 
feet pinkish buff; hind feet cartridge buff, the thighs pinkish cin- 
namon or mikado brown; tail above, pinkish cinnamon on proximal 
third, the remainder fuscous black, broadly edged with cartridge 
buff (the basal portion of the hairs likewise cartridge buff) ; tail 
beneath, russet, bordered with fuscous black and tipped with car- 
tridge buff; under parts and lower sides cartridge buff. 

Measuremeiits. — Average of 7 adults (4 males, 3 females) from type locality: 
Total length, 221.7 (214-227) ; tail vertebrae, 78 (70-81) ; hind foot, 30.4 
(29-32). »S7.w 7?.- Average of 4 adult males: Greatest length, 37 (37-37.1); 
palatilar length, 17.3 (17-17.5) zygomatic breadth, 21.4 (21.1-21.7) ; cranial 
breadth, 16.6 (16.3-17) ; interorbital breadth, 7.8 (7.3-8) ; postorbital constric- 
tion, 11.7 (11.3-12.3) ; length of nasals, 12.7 (12.5-13) ; maxillary tooth row, 
5.9 (5.7-6.1). Average of 3 adult females: Greatest length, 35.8 (35-36.1); 
palatilar length, 16 (15.5-16.5) ; zygomatic breadth, 20 (one specimen) ; 
cranial breadth, 15.9 (15.7-16.4) ; interorbital breadth, 7.2 (7.1-7.3) ; postorbital 
constriction, 12 (11.7-12.2) ; length of nasals, 12.3 (11.8-12.8) ; maxillary tooth 
row, (5.6-6.2). 

Remarks. — This race is similar to alleni of the Bighorn Moun- 
tains, Wyo. ; it resembles, also, hollisteri of eastern New Mexico, but 
is somewhat paler and differs in the color of the under side of the 
tail. Typical specimens are known only from the higher parts of 
the White Mountains, Ariz.; specimens from Springerville, at the 
base of the mountains and from the Datil Mountains, N. Mex., agree 
with parvus in the coloration of the tail and in skull characters, but 
are about as dark as typical monticola., thus indicating intergrada- 
tion between these forms. 

Specimens examined. — Total number, 7, from Marsh Lake, Wliite 
Mountains, Ariz. 

CITELLUS TRIDECEMLINEATUS PARVUS (Allehst) 

Least Striped GRor?7D Sqtjibkel 

Spcrmophilus trideccmlineatus parvus Allen, Amer. Mus. Nat. Hist. Bull. 7: 

337, Nov. 8, 1895. 
[Citellus tridecimlhieatus] parvus Trouessart, Cat. Mamm., Sup., p. 341, 1904. 

Ty/^e.— Collected at Kennedy's Hole, Uncompahgre Indian Reser- 
vation (20 miles northeast of Ouray, Uintah County), Utah, May 2, 
1895, by W. W. Granger; male adult, skin and skull, no. W^, Amer. 
Mus. Nat. Hist. (ori<2^. no. 537). 

Range. — Uncompahgre Plateau, eastern Utah and desert regions 
of southwestern Wyoming, northwestern and south-central Colorado, 
and west-central New Mexico ; north to Natrona County, AVyo. ; east 
to Independent Kock, Wyo., south to St. Augustine Plains, N. Mex.; 
and west to Springerville, Ariz. (fig. 9). Zonal range: Upper 
Sonoran. 



llg NORTH AMERICAN FAUNA [No. 56 

External characters. — Similar to G. t. arenicola but much smaller 
and slightly darker ; median pair of light dorsal stripes more or less 
broken into spots; tail not reddish beneath. Compared with G. t. 
■pallidus: Size much smaller and coloration more reddish. 

Cranial characters. — Skull similar to that of C. t. alleni but slightly 
smaller and relatively broader, with shorter nasals and larger audital 
bullae; decidedly smaller than those of arenicola and pallidus. 

Color. — Winter pelage (type, May 2) : Front of face dull pinkish 
buff ; top of head sayal brown, mottled with grayish white ; eye ring 
buff'y white; dark dorsal stripes walnut brown; light stripes and 
spots creamy white; sides of head and neck and front feet washed 
with pinkish buff; hind feet dull whitish; tail above and below, 
pinkish cinnamon, shading to fuscous on distal half, overlaid with 
grayish white; under parts white. Summer pelage (Bitter Creek, 
Wyo., August) : Dark dorsal stripes snuff brown ; tail heavily over- 
laid on both surfaces with cinnamon buff. 

Measurements. — Average of 5 adult males from Utah (the type and^ others 
from Ouray) : Total length, 189 (170-202) ; tail vertebrae, 71 (69-72) ; hind foot, 
28 (27-29), Average of 12 adults from Bitter Creek, Wyo., and Snake River, 
Colo.: 204.6 (189-228) ; tail vertebrae, 76.7 (65-87) ; hind foot, 32.9 (28-31). 
Skull: Average of 4 adult males (type from Utah ; 2 from Bitter Creek, Wyo.; 
one from Snake River, Colo.) ; Greatest length, 35.3 (34.6-36.2) ; palatilar length, 
15.5; zygomatic breadth, 20.2 (19.7-21); cranial breadth, 16.7 (16.4-17.3); in- 
terorbital breadth, 7.1 (6.9-7.3) ; postorbital constriction, 11.4 (11.1-11.7) ; 
length of nasals, 11.7 (10.5-12.7) ; maxillary tooth row, 6.2 (5.9-6.4). Average 
of 4 adult females (Ouray, Utah, Bitter Creek, Wyo., and Routt County, Colo.) : 
Greatest length, 33.9 (33.2-34.3) ; palatilar length, 14.9 (14.5-15.5) ; zygomatic 
breadth, 19.4 (19.1-19.7) ; cranial breadth, 16.1 (15.8-16.4) ; interorbital 
breadth, 7.1 (7-7.2) ; postorbital constriction, 11.2 (11-11.5) ; length of nasals, 
10.5 (10-11) ; maxillary tooth row, 6.2 (6-6.4). 

Weight. — One female weighed 6 ounces. 

Remarks. — This subspecies is the smallest of the races of G. tride- 
cemlineatus and is about as pale as arenicola from western Kansas. 
Its range is imperfectly known at present and appears to be discon- 
tinuous. A good series from Bitter Creek, southwestern Wyoming, 
appears to be typical and a few specimens from northwestern Colo- 
rado are also referred to this race, although they average darker; 
and those from Lay, Rangely, and Mud Springs might on the basis 
of color be referred to alleni. Their skulls, however, are small, like 
those of parvus. A series from the San Luis Valley, southern 
Colorado, is provisionally referred to parvus, although they show 
some color variations that may necessitate their separation when it 
is possible to compare them with a good series of topotypes. Inter- 
gradation with G. t. monticola of southern Arizona is indicated by 
small series from Datil Mountains, N. Mex., and Springerville, Ariz. ; 
with alleni by specimens from New Fork of Green River, Wyo., and 
with pallidus by specimens from Casper, Wyo. (referred to pallidus). 

Specimens examined. — Total number, 69, as follows: 

Arizona: Springerville, 4. 

Colorado: Antonito, 2; Axial Basin (12 miles southeast of Lay), 2; Escalante 
Hills (Moffat County), 1; Fort Garland, 3; Medano Ranch (Alamosa 
County), 2;" Mosca (Alamosa County), 1;" Muddy Creek (Huerfano 
County), 1;"; Mud Springs (Garfield County, 30 miles southeast of 
Meeker), 4;" Rangely (Rio Blanco County), 2; San Acacio (Costilla 
County), 3;" San Luis Lakes (Alamosa County), 1;" Snake River (Mo(- 



1938] REVISION OF THE GROUND SQUIRRELS HQ 

fat County), 5;"" Two Bar Spring (western Moffatt County), 1;" West- 
cliff e (Custer County), 7. 
New Mexico: Datil Mountains (12 miles northwest of Datil), 2; St. Augustine 

Plains (near Monica Spring), 2. 
Utah: Fruitland, 3;" Ouray (12 miles southwest), 4;" Uncompahgre Indian 

Reservation, 4." ^^ 
Wyoming: Big Sandy (Sublette County), 1; Big Sandy Creek (Lander Road), 

1; Bitter Creek (Kinney Ranch, Sweetwater County), 9;" Green River, 1; 

Independent Rock (mouth of Dry Creek, Natrona County), 1; Myersville 

(Fremont County), 1; Sun (Natrona County), 1. 

CITELLUS MEXICANUS (Eexlb35En) 
[Synonymy under subspecies] 

Specific characters. — Size large; hind foot 38-51 mm; tail about 
40 percent of the total length ; skull length, 41-52.5 mm. Skull sim- 
ilar to that of C. tridecemlineatus but considerably larger ; brain case 
less elongate, more nearly square ; zygomata more widely expanded ; 
audital bullae large and smoothly rounded. Ears broad and low, 
rising 3-5 mm above crown. Coloration of upper parts varying 
from wood brown or buffy brown to sayal brown or snuff brown, 
marked with squarish white spots arranged in linear rows, usually 
nine in number, the spots sometimes partly confluent, at other times 
more or less obsolete; head buffy brown or wood brown, sprinkled 
with white, the nose clay color or cinnamon buff; feet, sides, and 
under parts white to pinkish buff; tail above, mixed fuscous and 
grayish or buffy white; tail beneath, avellaneous to cinnamon buff, 
more or less obscured by grayish or buffy white. 

CITELLUS MEXICANUS MEXICANUS (Erxleben) 

Mesican Ground Squirkex 

(Pis. 25, C; 30, C) 

[8ciuru8'\ mexicanus Erxleben, Syst. Regni Anim. 1 : 428, 1777. 

Citillus mexicanus Lichtensteiu, Darstel. Saugt., plate 31 (and accompanying 

text), 1827-1834. 
Spermophilus mexicanus Wagner, Schreber's Siiugt., Sup., 3: 250, 1843. 
Otospermophilus mexicanus Brandt, CI. Phys.-Math. Acad. Sci. St. Petersbourg 

Bull. 2 : 379, 1844. 
Citellus mexicanus Merriam, Biol. Soc. Wash. Proc. 16 : 80, 1903. 

Type. — None designated ; type locality fixed at Toluca, Mexico, bv 
Mearns (1896, p. 443). 

Range. — Central Mexico, from northern Jalisco and Guanajuato 
south to southern Puebla (fig. 10). Zoiuil range: Lower Sonoran. 

External characters. — Size large; hind foot, 46.5-51 mm; skull 
length, 45.3-52.5; coloration averaging darker, with more buffy 
sides and under parts than in C. m. parvidens. 

Cranial characters. — Skull similar to. that of G. tHdecemlineatus 
tridecemlineatus but much larger; brain case relatively broader; 
audital bullae larger and more inflated. 

Color. — Upper parts buffy brown, sayal brown, or snuff brown, 
the dorsum covered with numerous squarish white spots arranged in 
nine linear rows (sometimes with indications of another pair of lines 

^ E. R. Warron collection. 
« Colo. Mus. Nat. Hist. 
" Amer. Mus. Nat. Hist, 
i"^ Field Mus. Nat. Hist. 
" Carnegie Mus. 



120 



NORTH AMERICAN FAUNA 



[No. 56 



on lower sides), the middle row usually somewhat narrower than 
the others; the lines sometimes irregular and broken in middle of 
back, and spots sometimes confluent on some of the rows ; head buff y 
brown, with whitish tips to some of the hairs; nose and front of 
face cinnamon buff or clay color; eye ring white; feet pinkish buff 
or cartridge buff; tail above, mixed fuscous and buffy white, with 

some of the body color 
near the base ; tail be- 
neath, avellaneous to 
cinnamon buff, bor- 
dered with fuscous 
and edged with buffy 
white. 

Measurements. — ^Aver- 
age of 10 adults and sub- 
adults from central Mex- 
ico (states of Hidalgo, 
Queretaro, Guanajuato, 
and Mexico): Total 
length, 349.6 (322-380) ; 
tail vertebrae, 144.6 (124r- 
166) ; hind foot, 48.4 
(46.5-51). Skull: Aver- 
age of 13 adults (6 males, 
7 females) from Quere- 
taro, Guanajuato, and Ja- 
lisco : Greatest length, 49 
(45.3-52.5) ; palatilar 
length, 23.5 (22-24.2) ; 
zygomatic breadth, 28.9 
(27-30.3); cranial 
breadth, 20.4 (19.3-21.1) ; 
interorbital breadth, 10.4 
(9.6-11.1) ; postorbital 
constriction, 14 (13.2- 
14.8) ; length of nasals, 
17.8 (15.8-20.1); maxillary 
tooth row, 9.8 (9.3-10.5). 

Remarks. — This 
strikingly marked 
ground squirrel was 
one of the first North 
American species to 
be recognized, having 
been named by Erxle- 

FiGOKE 10. — Distribution of the subspecies of Citellus mexi- l-\pn in 1777 Tt tq pnm- 
canus; 1, V. m. parvidens; 2, C. m. mexicanus. ' * T , ? ^ \ 

mon on the tableland 
of central Mexico, occupying an area lying mainly south of the range 
of 0. spilosoma. It resembles this species only slightly, being much 
larger and more heavily spotted. It varies considerably in color; 
the extremes of coloration might be designated as a brovvn phase 
and a drab or olivaceous phase, but there are several intermediate 
shades in any large series of specimens. 

Specimens examined. — Total number, 31, as follows: 

Guanajuato : Celaya, 1 ; Silao, 3 ; Irolo, 1 ; Marques, 1. 

Jalisco: Atemajac, 7; Lagos, 2; Zapotlan, 6. 

Mexico: Tlalpam (Federal District), 4. 

Puebla: Atlixco, 1 ; San Andres Chalchicomula, 1 ; San Martin, 1. 

Queretaro: Tequisquiapan, 2. 

Tlaxcala: Huamantla, 1. 




1938] REVISION OF THE GROUND SQUIRRELS 121 

CITELLUS MEXICANUS PARVIDENS (Meaens) 
Rio Grande Ground Sqxjibbei, 

Spermophilus mexicanus parvidens Mearns, U. S. Natl. Mus. Proc. 18: 443, 

May 23, 1896 (advance sheets issued, Mar. 25, 1896). 
[Citelliis mexicanus^ parvidens Elliot, Field Columb. Mus., Zool. Ser. 4: 146, 

1904. 

Type. — Collected at Fort Clark, Kinney County, Tex., March 21, 
1893, by E. A. Mearns; male adult, skin and skull, no. 63073, U. S. 
Natl. Mus. (orig. no. 2312). 

Range. — Northeastern Mexico, ^Yestern Texas, and southeastern 
New Mexico ; north to Eoswell, N, Mex. and Borden County, Tex. ; 
east to Austin and Rockport, Tex.; south to southern Tamaulipas; 
west to central Coahuila and extreme western Texas (El Paso) (fig. 
10). Zonal range: Lower Sonoran. 

External characters. — Similar to C. m. mexicanus but decidedly 
smaller; coloration averaging paler, with less buff on under parts 
and hind legs. 

Cranial characters. — Skull similar to that of mexicanus but 
decidedly smaller. 

Color. — Upper parts varying from wood brown to sayal brown or 
snuff brown, with nine usually distinct linear rows of large white 
spots; head same color as back, flecked with white; nose patcli cin- 
namon buff; eye ring white ; sides of face and neck smoke gray; sides 
of body and under parts creamy white or cartridge buff; hind legs 
cinnamon buff to cartridge buff; feet pinliish buff or buffy white; 
tail above, mixed fuscous and buffy white; tail beneath, cartridge 
buff or pinkish buff, more or less overlaid with buffy white. 

Measurements. — Average of 12 ndults from type locality: Total length, 300.S 
(280-313); tail vertebrae, 118.3 (110-126); hind foot, 40.9 (38-43). Skull: 
Average of 17 adults (9 males, 8 females) from type locality: Greatest length, 
43 (41.1-44.8) ; palatilar length, 20.7 (10.5-22) ; zygomatic breadth, 25.3 
(23.5-27.1) ; cranial breadth, 18.6 (17.S-19.5) ; interorbital breadth, 9.4 (8.2- 
10.5) ; postorbital constriction, 12.7 (12-14.6) ; length of nasals, 15.1 (13.5- 
16.2) ; maxillary tooth row, 8 (7.3-8.9). 

Remarhs. — This northern race of mexicanus is distinctly larger 
than the typical race, and, like it, shows a great amount of variation 
in color; the majority of specimens of parvidens are paler than mex- 
icanus but some in the brown phase are not appreciably different in 
color. 

Although actual integradation with mexicanus is not shown by 
the material in hand, it seems highly probable that additional col- 
lecting in Mexico, particularly in &an Luis Potosi, will result in the 
discovery of intergrades. 

Specimens examined. — Total number, 225, as follows: 

Coahuila: Las Vacas, 1; Monclova, 1; Sabinas, 1; Saltillo, 8. 

New Mexico: Carlsbad, 2; Roswell, 3. 

Nuevo Leon: Montemorelos, 1; Pesqueria Grande (probably near Monterey), 1; 

Santa Catarina, 1. 
Tamaulipas: Bagdad, 3; Camargo, 2; Mier, 5; Nuevo Laredo, 1; Reynosa, 1; 

Victoria, 1. 
Texas: Adams (Pecos County), 2; Alice, 1; Alpine, 1; Altuda (Brewster 

County), 7 ; Beeviile, 1 ; Big Spring, 2 ; Brownsville, 20 ; Cameron County, 7 ; 

Carrizo Springs, 2 ; Colorado, 4 ; Comstock, 3 ; Concho County, 1 ; Corpus 

Christi, 9;" Cotulla, 3; Del Rio, 3; Devils River (at mouth), 2; Eagle 



" Three in Field Mus. Nat. Hist. 



122 NORTH AMERICAN FAUNA [No. 56 

Pass, 3; East Painted Cave (near moutli of Pecos River), 1; Fort Clark 
(Kinney County), 33; Fort Lancaster (Crockett County), 6; Fort Stockton 
(25 miles west), 2; Juno (Val Verde County), 1; La Hacienda (10 miles 
southeast of Hidalgo), 1; Langtry (Val Verde County), 15; Laredo, 5; 
Lomita Ranch (Hidalgo County), 2; Lozier (Terrell County), 1; Marathon, 
1; Mason, 1; Monahans (Ward County), 4; Norias (Kenedy County), 2; ^*° 
Pecos, 4; Port Isabel, 14:^^ Rio Grande City, 5; Rock Springs (10 miles 
west), 1; Rockport, 1;" Samuels (Val Verde County), 4; San Angelo 1; 
San Diego, 5; Sarita (Kenedy County), 3;"" Sheffield (Pecos County), 3; 
Stanton, 3; Sycamore Creek (Val Verde County), 3. 

CITELLUS SPILOSOMA GROUP 

CITELLUS SPILOSOMA (BENNETtT) 

[Synonymy under subspecies] 

Specific characters. — Size small to medium; hind foot, 28-38 mm; 
tail, 55-88 ; skull length, 34.1-42.7. Skull similar to that of C. tri- 
decemlineatus., but relatively shorter and broader, especially the 
rostrum and interorbital region ; audital bullae much larger. 

Color. — Upper parts drab, cinnamon drab, avellaneous, smoke gray, 
fawn, wood brown, snuff brown, or verona brown, more or less spotted 
with squarish white spots; tail above, usually similar to the back, 
darkened at the tip with fuscous black; tail beneath, pinkish buff, 
pinkish cinnamon, vinaceous cinnamon, or cinnamon buff. 

CITELLUS SPILOSOMA SPILOSOMA (Bennett) 

Bennett's Spottbh) Ground Sqtjirebl 

(Pis. 25, A; 30, A) 

Spermophiliis spilosoma Bennett, Zool. Soc. London Proc. 1833 : 40. 
Citellus spilosoma Allen, Amer. Mus. Nat. Hist. Bull. 20 : 209, 1904. 

Lectotype (Thomas, 1927, p. 548).— No. 53.8.29.5, British Museum; 
male, skin (without skull), from an unknown locality; in the absence 
of any definite information relative to the type, the type locality is 
hereby fixed at Durango, Durango.^^ 

Range. — Central Mexico, from Durango City south to Aguas- 
calientes; east to San Luis Potosi (city) (fig. 11). Zonal range: 
Lower Sonoran. 

External characters. — Size large ; tail long, with considerable black 
at distal end; dorsal spotting rather fine, becoming obsolete on the 
anterior part of the body. 

Cranial characters. — Skull similar in shape to that of C. mexicanus 
mexicanus but much smaller; similar to that of C. tridecemlineatus 
texensis but with broader brain case and larger audital bullae. 

Color. — (Jesus Maria, San Luis Potosi, Sept. 10) : Upper parts 
fawn color, moderately speckled, chiefly on hinder back, with small 
squarish spots of white; eye ring buffy white; sides of faca neck, 
and shoulders washed with smoke gray ; front feet pinkish buff ; hind 
feet cartridge buff • tail above, vinaceous fawn, the hairs on the distal 
half with a broad subterminal band of black, tipped with buffy 
white; tail beneath, vinaceous cinnamon, more or less obscured by 
black and edged with buffy white; under parts white, tinged with 
pale buff. 



« Field Mus. Nat. Hist. 
isaAcad. Nat. Sci. Philadelphia, 
"See remarks, p. 123. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



123 



A specimen from Durango, Durango, June 27 (said to agree closely 
with the type) is slightly more reddish above than this description, 
the general tone about vinaceous fawn. 

Measurements. — Average of 11 adults from Aguascalientes and San Luis 
Potosi (Jesus Maria and Hacienda La Parada) : Total length, 238.4 (230-250) ; 
tail vertebrae, 77.7 (71-88); hind foot, 35.8 (34-37). Skull: Average of 11 
adults (2 males, 9 females) from San Luis Potosi and Zacatecas : Greatest 

length, 40.9 (39.3-42.7) ; 

1^ J J \ n palatilar length, 1S.8 

'■^•"-ll, i "C K""^ (18.2-19.8) ; zygomatic 

. ^ >. 1 breadth 24.5 (23-26.6) ; 

cranial breadth, 18.6 
(17.8-20) ; interorbital 
breadth, 8.8 (8-10) ; post- 
orbital constriction, 14.2 
(13.1-15.9) ; length of na- 
sals, 14.2 (13.7-15.2) ; 
maxillary tooth row, 7.6 
(7-8). 

Re^narJcs. — Origi- 
nally described in 1833 
from an unknown lo- 
cality, this species has 
never been fully char- 
acterized and it seems 
impossible to discover 
the exact source of the 
type specimens. They 
were stated by the de- 
scriber to have been 
obtained in "that part 
of California which 
adjoins to Mexico." 
Baird (1857, p. 322) 
states: "this species 
was first described 
from specimens col- 
lected on the western 
coast of Mexico", but 
does not give the 
source of his informa- 
tion. However, since 
the species is not 
known to occur to the 
westward of the Si- 
erra Madre in Mexico, this statement cannot be taken literally. 

At the time the species was described (1833), few expeditions had 
been made to the region where it lives. Capt. Beechey's expedition, 
however, remained at San Bias, on the coast of Tepic, from December 
8, 1827, to February (?), 1828, and Mr. Lay, the naturalist of the 
expedition, "visited and remained for a long time at Tepic, 54 miles 
from San Bias, inland" (Hooker and Arnott, 1841, p. 1), and it seems 
not at all improbable that the type specimens may have been obtained 
by this expedition. 

In order to settle, if possible, the identity of typical spilosoma, 
several specimens of this species from central Mexico and several from 




Figure 11. — Distribution of Citellus perotcnsis and of the 
subspecies of C. spUosoma: 1, O. s. obsoletus ; 2, C. 8. 
pratensis; 3, C. s. cruptospllotus ; 4, C. a. major; 5, G. s. 
canescens; 6, C. s. annectens ; 7, C. s. pallescens ; 8, 0. 8. 
spiloaovia; 9, C. perotensis. 



124 NORTH AMERICAN FAUNA [No. 56 

southern Arizona {C. s. canescens) Avere forwarded to the late Old- 
field Thomas, at the British Museum, who kindly compared them with 
the cotypes in that institution. He wrote as follows : 

After a careful comparison it appears to me that the large form from 
TDurango], central Mexico (No. 9459S, U. S. N. M.) most nearly agrees with the 
type of spilosoma, though unfortunately the latter has no skull to give an abso- 
lute indication of size ; the feet, however, would appear to be quite as large as 
in your specimen. The only difference is that our specimens are of a rather 
stronger cinnamon colour anteriorly, especially on the crown, less greyish. 

This decision will involve no shifting of names, since the other de- 
scribed forms in the group are all recognizably different from this 
race. 

Specimens examined. — Total number, 39, as follows: 

Aguascalientes : Chicalote, 14. 
Durango: Durango, 13. 
San Luis Potosi: Jesus Maria, 2. 
Zacatecas: Berriozabal, 10. 

CITELLUS SPILOSOMA PALLESCENS Howell 

P^u.LiD Spottjcd Geound Squireel 

Citellus spilosoma pallescens Howell, Biol. Soc. Wash. Proc. 41 : 212, Dec. 18, 1928. 

Type. — Collected at La Ventura, Coahuila, August 10, 1896, by 
E. W. Nelson and E. A. Goldman; male adult, skin and skull, no. 
79535, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 
10016). 

Range. — North-central Mexico from southern Chihuahua (Santa 
Rosalia) southward to San Luis Potosi and eastward to southern 
Nuevo Leon (Doctor Arroyo) (fig. 11) . Zonal range: Lower Sonoran. 

External characters. — Similar to G. s. spilosoma., but paler. Com- 
pared with G. s. canescens : Size larger ; tail longer, with more black 
on distal half ; dorsal spotting finer. 

Granial characters. — Skull similar to that of spilosoma but aver- 
aging smaller, with shorter, broader rostrum and nasals ; larger than 
that of G. s. canescens, with longer, narrower rostrum. 

Golor. — (August specimens, topotypes) : Upper parts wood brown 
or drab, finely speckled, chiefly on hinder back, with white ; tail above, 
light pinkish cinnamon on proximal half, the distal half bordered 
with fuscous black and edged with buffy white ; tail beneath, pinkish 
buff, bordered with fuscous black and buffy white; otherwise as in 
spilosoma. 

Measurements. — Average of 12 adults from La Ventura and Carneros, Coa- 
huila: Total length, 242.6 (232-253); tail vertebrae, 84.8 (76-92); hind foot, 
35.7 (34.5-37). Skttll: Average of 10 adults from La Ventura: Greatest length, 
40.1 (38.9-41.1) ; palatilar length, 17.9 (17.2-18.5) : zygomatic breadth, 23.8 
(22.9-24.5) ; cranial breadth, 18.6 (18.2-19) ; interorbital breadth, 8.4 (7.8-8.9) ; 
postorbital constriction, 14 (12.8-15.1; length of nasals, 18.6 (13-14.5) ; maxil- 
lary tooth row, 7.5 (7.1-8.1). 

Bemarks. — This pale race, occupying the plains of north-central 
Mexico, is most nearly related to spilosoma. It intergrades with both 
spilosoma and canescens. A large series from Santa Eosalia, Chihua- 
hua, is nearest to pallescens., but shows approach to canescens in the 
coarser spotting of some individuals and in the size and shape of 
some of the skulls. 



19381 REVISION OF THE GROUND SQUIRRELS 125 

Specimens examined. — Total number, 75, as follows : 

Chihuahua: Escalon, 4; Santa Rosalia, 20. 

Coahuila: Carneros, 6; Jaral, l;"" La Ventura, 17; Torreon, 6. 

Nuevo Leon : Doctor Arroyo, 2. 

San Luis Potosi: Hacienda La Parada (about 20 miles northwest of San Luis 

Potosi), 17; San Luis Potosi, 1. 
Zacatecas: Caiiitas, 1. 

CITELLUS SPILOSOMA CANESCENS (Mebbiam) 

Apache Spotted Geoxjnd Sqttieeel 

(PI. 5) 

Spermophilus canescens Merriam, North Amer. Fauna 4 : 38, Oct. 8, 1S90. 
Spermophilus spilosoma macros irilot us Merriam, Ibid., p. 38, (Oracle, Ariz.). 
Anisonyx (.Xerospermophilns) canescens Allen, Amer. Mus. Nat. Hist. Bull. 7: 

239, 1895. 
Anisonyx {Xero spermophilus) spilosoma macrospilotus Allen, loc. cit., p. 239, 

1895. 
[Spermophilus spilosoma] microspilotus Elliot, Field Columb. Mus. Pub. Zool. 

Ser. 2: 96, 1901 (accidental renaming of macrospilotus). 
Spermophilus spilosoma arens Bailey, Biol. Soc. Wash. Proc. 15 : 118, 1902 (El 

Paso, Tex.). . 
Citellus spilosoma microspilotus Elliot, Field Columb. Mus. Pub., Zool. Ser. 4 : 

144, 145, 1904. 
Citellus spilosoma macrospilotus Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 

99, 1905. 
Citellus spilosoma canescens Bailey, North Amer. Fauna 53 : 109, 1931. 

Type. — Collected at Will cox, Cochise County, Ariz., November 16, 
1889, by Vernon Bailey; male juv,, skin and skull, no. ^-||^^, U. S. 
Natl. Mus. (Biological Survey collection) (orig. no. 676). 

Range. — Southeastern Arizona and southwestern New Mexico; 
south to Chihuahua City, Chihuahua, Mexico ; west to Altar Valley, 
Ariz.; north to Gila Valley (Pima), Ariz.; east to Deming, N. Mex. 
and Fort Hancock, Tex. (fig. 11). Zonal range: Lower Sonoran. 

External characters. — Similar to G . s. pallescens, but smaller, with 
shorter tail and hind feet; dorsal spots larger, and more numerous 
on f oreback ; tail with more black on distal portion. 

Cranial characters. — Skull similar to that of pallescens, but smaller, 
with shorter, broader rostrum. 

Color. — Cinnamon phase (January) : Upper parts fawn color, 
thickly spotted over most of the back with rather large, quadrangular 
whitish spots, more or less obscured or obsolete on the f oreback; a 
broad white ring surrounds the eye ; sides of nose whitish ; sides of 
body washed with pinkish buff; front feet cartridge buff: hind feet, 
white; tail above, vinaceous fawn, edged with pinkish buff, the hairs 
on distal half with a subterminal band of fuscous black; tail beneath, 
cinnamon buff with a narrow band of fuscous black near the tip; 
under parts white. Worn specimens in spring (April and May) 
have the tail considerably darker — dull orange cinnamon. D7'ab phase 
(May) : Upper parts light drab or light cinnamon drab, spotted as in 
the cinnamon phase ; sides whitish or with a very faint wash of pale 
ivory yellow. 

Measurements. — Average of 11 adults from Willcox, Ariz.: Total length, 
228.5 (210-247) ; tail vertebrae, 73.8 (07-86) ; hind foot, 32.1 (30-34). Skull: 
Average of 10 adults (4 males, 6 females) from Willcox and Oracle, Ariz. ; 



» Field Mus. Nat. Hist. 



126 NORTH AMERICAN FAUNA [No. 56 

Greatest length, 38.1 (37.5-38.7) ; palatilar length, 17 (16.a-17.5) ; zygomatic 
breadth, 23.2 (23-23.9) ; cranial breadth, 18.1 (17.6-19.2) ; interorbital breadth, 
8.3 (7.5-8.9) ; postorbital constriction, 13.8 (13-14.4) ; length of nasals, 12.8 
(11.6-13.5) ; maxillary tooth row, 7.2 (6.5-7.4). 
Weight. — Two specimens weighed respectively, 81.5 and 93.4 g. 

Remarks. — The Apache ground squirrel is j-eadily distinguished 
from the central Mexican forms {(J. s. spilosoma and pallescens) 
by the larger and more numerous dorsal spots. Specimens from 
Chihuahua City are typical, but south of that point intergradation 
with pallescens occurs. Specimens from El Paso and Fort Han- 
cock, Tex., are intermediate between canescens and C. s. major. The 
range of this form northward in Ai'izona apparently is limited by 
the Mogollon Plateau. 
Specimens examined. — Total number, 125, as follows : 

Arizona: Buenos Ayres, Altar Valley, 1; Chiricahua Mountains (2 miles south- 
east of Moore's Ranch), 1;^^ Fort Bowie (Cochise County), 1; Fort Grant 
(Graham County), 1; Fort Huachuca, 9; Huachuca Mountains, 3;^" La 
Noria, Santa Cruz River, 1 ; Mowry, Patagonia Mountains, 2 ; Oracle (Pinal 
County), 6; Pima, 1; Tombstone, 2; Tucson (24 miles southeast), 1; 
Willcox, 24. 

Chihuahua : Casas Grande, 4 ; Chihuahua, 15 ; Lake Palomas, 1 ; White Water, 
Mexican boundary line, 1. 

New Mexico: Apache (Grant County), 1 ; Deer Creek (Hidalgo County), 2; Dem- 
ing, 2; Dog Spring (Grant County), 7; Fayvrood (Grant County), 1; 
Hachita, 3; Mangos Valley (Grant County), 1; Monument 15, Mexican 
boundary line, 4; Monument 40, Mexican boundary line, 2; SUver City, 
2 ; Warren, 6 ; "" Whitmire Pass, Playas Valley, 1. 

Texas: El Paso, 10; Fort Hancock (El Paso County), 9. 

CITELLUS SPILOSOMA MAJOR (Merkiam) 

New Mexico Spotted Geotjnd Squierel 

SpermopMlus spilosoma major Merriam, North Amer. Fauna 4 : 39, Oct. 8, 1890. 
Spermophilns spilosoma marginatus Bailey, Biol. Soc. Wash. Proc. 15: 118, 

1902 (Alpine, Tex.). 
[Citellus stnlosoma] major Trouessart, Cat. Slamm., Sup., p. 340, 1904. 

Type. — Collected at Albuquerque, N. Mex., July 22, 1889, by Ver- 
non Bailey; female adult, skin and skull; no. Hm, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 225). 

Range. — Eastern New Mexico, western Texas, western Oklahoma, 
south Avestern Kansas and southeastern Colorado; north to Adams 
and Yuma Counties, Colo. ; east to Kinsley, Kans., Woodward, Okla., 
and Colorado, Tex. ; south to Presidio and Brewster Counties, Tex. ; 
west to St. Augustine Plains, N. Mex. (fig. 11.) Zonal range: Upper 
Sonoran. 

External characters. — Similar to G. s. canescens.^ but hind feet 
larger; dorsal spots fewer and less distinct. 

Cranial characters. — Skull similar to that of canescens., but larger, 
with decidedly longer nasals. 

Color. — Upper parts varying from light cinnamon-drab or avella- 
neous to fawn color or mikado brown (in worn specimens), spar- 
ingly spotted on the back with m.ore or less indistinct white spots; 
front feet pinkish buff; hind feet buffy white; tail above, usually 
same color as the back, the hairs on distal portion with a subterminal 



SI Acad. Nat. Sci. Philadelphia. 
2ia Carnegie Mus. 



1938] REVISION OF THE GROUND SQUIRRELS 127 

band of fuscous; tail beneath, light pinkish cinnamon, pinkish buff, 
or light vinaceous cinnamon; under parts and sides white, some- 
times washed with cartridge buff. 

Measriremcnts. — Average of 8 adults (3 males, 5 females) from Albuquerque 
and Isleta, N. Mex. : Total length, 231.7 (221-245) ; tail vertebrae, 76.7 (69-80) ; 
hind foot, 35.2 (34-36). Skull: Average of 10 adult males from New Mexico 
(Albuquerque, Espaiiola, Capitan Mouutains) and southern Colorado (La 
Junta, and Las Animas County) : Greatest length, 40.9 (39.7-42.5) ; palatilar 
length, 18.6 (18-19.5) ; zygomatic breadth, 24.3 (23.5-25.6) ; cranial breadth, 
18.9 (17.9-19.9) ; interorbital breadth, 8.6 (8.1-9.1) ; postorbital constriction, 
13.7 (12.6-14.8) ; length of nasals, 14.4 (13.5-15.5) ; maxillary tooth row, 7.6 
(7-8). Average of 10 adult females from New Mexico (Albuquerque, Espaiiola, 
Isleta, Carrizozo, Capitan Mountains) ; Greatest length, 40.4 (39-41.5) ; 
palatilar length, 18.2 (17.5-18.8) ; zygomatic breadth, 24.1 (23.4-24.9) ; cranial 
breadth, 18.7 (18.1-19.6) ; interorbital breadth, 8.5 (7.8-9.1) ; postorbital con- 
striction, 14 (13.4-14.5) ; length of nasals, 14.3 (13.2-15.2) ; maxillary tooth 
row, 7.5 (6.2-8). 

Remarks. — This wide-ranging form is distinguished from its near- 
est neighbors chiefly by its large size. The drab phase is compara- 
tively rare and does not appear in pure form — ^that is, many of the 
specimens are more or less intermediate between a drab and a cin- 
namon phase. Two specimens from 8 miles east of Deming, N. Mex., 
are typical majo?", while several others from Deming are best re- 
ferred to canescens. 

The present form passes insensibly into subspecies C. s. obsoletus; 
most of the specimens from eastern Colorado, north of the Arkansas 
Valley, are so completely intermediate between the two forms that 
it is very difficult to say which form they most resemble. The series 
from Las Animas, Colo., is clearly referable to major., the skulls 
being even larger than skulls of topotypes from New Mexico. Speci- 
mens from Tuttle, Wray, and Barr Lake show approach to obsoletus. 

The series from Alpine, Tex., on which was based the subspecies 
'"''marginaius'''' of Bailey, averages slightly darker than typical major^ 
all of them being in the cinnamon phase, but some specimens of the 
tAvo series are indistinguishable; no difference is apparent in the 
amount of black flecking on the back, which in both forms is very 
inconspicuous. 

Specimen.'^ examined. — Total number, 172, as follows: 

Colorado: Akron, 1;'* Barr Lake (Adams County), 1;^ Carrizo Creek (Baca 
County), 1;" Elbert County (between Mattison and Resolis), 1;" Foss- 
ton (Weld County), 2;** Hugo, 1; La Junta (18 miles south), 2; Lamar, 
3;"" Las Animas, 9; Monon (Baca County), 2;^ Regnier (Baca 
County), 1.'' 

Kansas : Morton County, 1 ; *^ Kinsley, 1. 

New Mexico: Alamogordo, 5; Albuquerque, 11; Bear Spring Mountains (north 
of Magdalena, Socorro County), 4; Cabra Springs (San Miguel County), 1; 
Capitan Mountains (northwest foothills), 6; Carlsbad ("Eddy"), 7; Car- 
rizozo, 1; Deming (8 miles east), 2; Espauola, 7; Fort Sumner (8 miles 
north), 1; Isleta, 4; Lake Valley (Sierra County), 1; Magdalena (10-15 
miles southeast), 2; Maxwell. 1;'* Mesilla, 3;*°" Ojo Caliento (northeast 
of Chloride, Sierra County), 1; Rio Alamosa (15 miles north of 0.jo Cali- 
ente), 1; Roswell (and 20 and 50 miles north), 17; St. Augustine Plains 
(Catron County, 12 miles north of Monica Spring), 10; San .Jon (Quay 
County), 1;** Santa Rosa, 7. 

22 Univ. Mich. Mu.s. Zool. 

« Colorarto Mus. Nat. Hist. 

^ E. K. Warren collection. 

^ Kansas Univ. Mus. Nat. Hist. 

*"Acad. Nat. Sci. Philadelphia. 

'^ State Collf'ge, New Mexico. 

* Cleveland Mus. Nat. Hist. 

■» Reading (Pennsylvania) Public Mus. 



]^28 NORTH AMERICAN FAUNA [No. 56 

Oklahoma: Woodward, 7. 

Texas : Alpine, 12 ; Canadian, 1 ; Colorado, 2 ; Lipscomb, 1 ; Mobeetie, 3 ; Mona- 
bans (Ward County), 15; Miami, 1; Pecos, 4; Presidio County, 1; Toyah- 
vale (Reeves County), 2; Valentine, 3; Van Horn (Culberson County), 1. 

CITELLUS SPILOSOMA ANNECTENS (Mekeiam) 

Padee Island Gkottnd Sqijieeel 

Spermophilus spilosoma annectens Merriam Biol. Soc. Wasb. Proe. 8 : 132, 

Dec. 28, 1893. 
[Gitellns spilosoma] annectens Trouessart, Cat. Mamm., Sup., p. 340, 1904. 

Type. — Collected at "The Tanks," 12 miles from Point Isabel, 
Padre Island, Tex., August 24, 1891, by Wm. Lloyd ; male adult, skin 
and skull, no. Htlt i U. S. Natl. Mus. (Biological Survey collection) 
(orig. no. 694). 

Range. — Lower Rio Grande Valley, Tex., and Gulf coast section 
from the mouth of the river north to Nueces River ; Padre and Mus- 
tang Islands (fig. 11). Zonal range: Lower Sonoran. 

External characters. — Closely similar in size and coloration to C. s. 
major. 

Cranial churacters. — Skull closely similar to that of major, but 
averaging slightly longer, and slightly broader interorbitally ; with 
slightly narrower brain case ; audital bullae smaller. 

Color. — (Worn summer pelage) : Upper parts avellaneous or smoke 
gray ; dorsal spots large but rather indistinct ; sides white, sometimes 
washed with cartridge buff; tail above, like the back, shaded on 
distal portion with fuscous and edged with pale cartridge buff; tail 
beneath, cinnamon or light pinkish cinnamon; feet light pinkish 
cinnamon or pinkish buff ; under parts soiled whitish. 

Measurements. — Average of 6 adults from type locality : Total length, 229 
(220-234); tail vertebrae, 64.2 (55-75); hind foot, 35.4 (33-38). SkuU: 
Average of 7 adults (6 males, 1 female) from tj^e locality: Greatest length, 41 
(40.5^1.5) ; palatilar length, 18.1 (17.5-19) ; zygomatic breadth, 23.8 (23.2-24.4) ; 
cranial breadth, 18 (17.6-18.5) ; interorbital breadth, 9 (8.5-9.3) ; postorbital 
constriction, 13.1 (12.1-14.1) ; length of nasals, 14.1 (13.4-14.6) ; maxillary tooth 
row, 13.1 (12.1-14.1). 

Remarks. — The Padre Island ground squirrel is evidently an off- 
shoot of major and shows no close relationship to the darker and more 
finely spotted forms in Mexico. Some form of this species has been 
reported from various points along the Rio Grande, up as far as the 
mouth of the Pecos River, but no specimens are available from that 
part of the valley ; therefore it is uncertain whether or not the range 
of annectens meets that of major. 

Specimens examined.- — Total number, 30, as follows: 

Texas : Mustang Island, 2 ; ^* Norias, 2 ; ^^ Padre Island, 21 ; Rio Grande River 
(at mouth), 1; Sarita, 4..'^^ 

CITELLUS SPILOSOMA PRATENSIS (Mereiam) 

Park Spotted Gbound Squiebel 

(Pls. 25, B\ 30, B) 

Spermophilus spilosoma pratensis Merriam, North Amer. Fauna 3 : 55, Sept. 11, 

1890. 
Spermophilus spilosoma obsidianus Merriam, North Amer. Fauna 3 : 56, 1890 

(Cedar Belt, northeast of San Francisco Mountain, Ariz.). 
[Citellus spilosomaJi pratensis Trouessart, Cat. Mamm., Sup., p. 340, 1904. 



2»«Acad. Nat. Scl, Philadelphia. 



1938] REVISION OF THE GROUND SQUIRRELS 129 

Type. — Collected at north base of San Francisco Mountain (pine 
plateau), Ariz., August 5, 1889, by C. Hart Merriam and Vernon 
Bailey; female adult, skin and skull, no. mif , U. S. Natl. Mus. 
(Biological Survey collection) (orig. no. 285). 

Range. — North-central Arizona, between the Grand Canyon and 
the Mogollon Plateau; west to Seligman and Aubrey Valley (fig. 11). 
Zonal range: Upper Sonoran and Transition. 

External characters. — Similar to C. s. canescens but smaller, with 
shorter tail and hind feet ; upper parts darker ; dorsal spots smaller ; 
tail darker, with more black on distal portion. 

Cranial characters. — Skull similar to that of canescens ., but de- 
cidedly smaller ; much smaller than that of C. s. major. 

Color. — General tone of upper parts near snuff brown or verona 
brown, many of the hairs, especially on shoulders, tipped with 
whitish, producing a hoary effect ; back thickly sprinkled with small 
white spots which become less distinct or obsolete on the shoulders; 
sides of nose and face grayish ; eye ring white ; sides of body some- 
times faintly washed with pale cartridge buff ; tail above, dark fawn 
color or mikado brown, the distal half mainly black or fuscous black, 
edged with pinkish buff or buffy white; tail beneath, pinkish buff, 
cinnamon buff, or pinkish cinnamon, more or less mixed with grayish 
white and fuscous black; feet whitish, washed with cartridge buff; 
under parts white. 

Measurements. — Average of 10 adults from San Francisco Mountain and 
vicinity of FlagstafP, Ariz.: Total length, 195.8 (185-210) ; tail vertebrae. 61.1 
(55-68); hind foot, 30.5 (28-33). SknU: Average of 11 adults (3 males, 8 
females) from San Francisco Mountain, Flagstaff, and Walnut Canyon: 
Greatest length, 35.5 (34.1-36.3) : palatilar length, 15.7 (15-16.5) : zygomatic 
breadth, 20.9 (20.2-21.7) ; cranial breadth, 17 (16.4-17.5) ; interorbital breadth, 
7.3 (6.9-8) ; postorbital constriction. 12.5 (11.5-13.6) ; length of nasals, 12.1 
(11.2-13.2) ; maxillary tooth row, 6.6 (6.2-7.8). 

Remarks. — The park spotted ground squirrel is the smallest form 
in the group. Although most resembling canescens., there is no evi- 
dence of intergradation with that race, the ranges of the two ap- 
parently being separated by the Mogollon Plateau. Intergradation 
with major is suggested, though not clearly shown by three specimens 
from Gallup and Thoreau, N. Mex., which agree closely with 
pratensis in external characters but have larger skulls. On the 
Painted Desert, this form passes into the subspecies C. s. crypto- 
spilotns. 

Specimens examined. — Total number, 62, as follows : 

Arizona: Aubrey Valley (Hualpai Indian Reservation), 1; Deadmans Flat 
(northeast of San Francisco Mountain), 9;'" Flagstaff (including 9 miles 
northwest and 12 miles northeast), 7; Grand Canyon (Bass Camp and 
Trash Tank), 8; Kendrick Peak (20 miles northwest of Flagstaff), 1; San 
Francisco Mountain, 20; Seligman, 1; Walnut Canyon (Coconino Natl. 
Forest). 15. 



3" Mus. Vert. Zool. 



154970—38- 



230 NORTH AMERICAN FAUNA [No. 56 

CITELLUS SPILOSOMA CRYPTOSPILOTUS (Mesitjiam) 
Desert Spotted Gkound Squirrel 

Spermophilus cryptospilotus Merriam, North Amer. Fauna 3 : 57, Sept. 11, 

1890. 
Anlsonyx (Xerospermophilns) cryptospilotus Allen, Amer. Mus. Nat. Hist. Bull. 

7: 240, 1895. 
\_Citellus] cryptospilotus Trouessart, Cat. Mamm., Sup., p. 341, 1904. 

Type. — Collected at "Tenebito" [=Dinnebito] Wash, Painted 
Desert, Ariz., August 17, 1889, by C. Hart Merriam; male juv., skin 
and skull no. ^^f, U. S. Natl. Mus. (Biological Survey collection) 
(orig. no. 374). 

Range. — Northeastern Arizona, southeastern Utah, southwestern 
Colorado, and northwestern New Mexico ; north to Monticello, Utah ; 
east to Thoreau, N. Mex. ; south to Holbrook, Ariz.; west to the 
Little Colorado River (fig. 11). Zonal range: Upper and Lower 
Sonoran. 

External characters. — Similar in size to C. s. pratensis.f but colora- 
tion paler and more reddish (less brownish) ; similar to C. s. major 
but much smaller ; dorsal spots smaller and more numerous. 

Cranial characters. — Skull similar to that of fratensis; smaller 
than that of major. 

Color. — Upper parts fawn color or avellaneous, rather heavily 
sprinkled on hinder back with small whitish spots ; sides washed with 
pinkish buff or cartridge buff; feet cartridge buff; tail above, like 
the back and edged with pinkish buff with a fuscous patch near the 
tip ; tail beneath, pinkish buff or light pinkish cinnamon ; under parts 
white. 

Measurements. — Average of 6 adults from Painted Desert, Ariz. : Total length, 
199.5 (190-210); tail vertebrae, 65 (58-72); hind foot, 31.8 (31-33). Skull: 
Average of 14 adults from Painted Desert (4) and Oraibi (10) : Greatest 
length, 36.2 (35.1-36.8) ; palatilar length, 15.9 (14.5-16.5) ; zygomatic breadth, 
21.0 (20.9-22.4) ; cranial breadth, 17.5 (16.3-1S.4) ; interorbital breadth, 7.9 
(7.2-8.6) ; postorbital constriction, 12.9 (11.9-13.8) ; length of nasals, 12.5 
(11.7-13.5) ; maxillary tooth row, 7 (6.3-7.4). 

Remarks. — The desert s])otted ground squirrel is closely related to 
' pratensis, its nearest neighbor on the west. The series from Wins- 
low, Ariz., indicates intergradation with major; specimens in the 
cinnamon phase agree in color with cryptospilotus while others in 
the drab phase closely resemble major; the skulls are somewhat 
larger than those of typical cryptospilotus. 

Specimens examined. — Total number, 42, as follows : 

Arizona: Chin Lee (15 miles southwest, Apache County), 1; Holbrook, 7; Oraibi 
(Navajo County), 13; Painted Desert, 6 (Diunebito Wash, 1; Moa Ave, 4; 
Tuba, 1) ; Winslow, 7. 

Colorado: McElmo Creek (south of Cortez, Montezuma County), 2.'^ 

New Mexico: Gallup, 3; Thoreau (McKinley County), 1. 

Utah: Lockerby (San Juan County), 1; Monticello (San Juan County), 1. 

CITELLUS SPILOSOMA OBSOLETUS (Kennicott) 

Kbnnicott's Spotted Ground Sqihebeil 

Sperriiophilns ohsoletus Kennicott, Acad. Nat. Sci. Phila. Proc. 1863: 157. 
ICitellusI obsoletus Trouessart, Cat. Mamm., Sup., p. 340, 1904. 



81 Colorado Agr. College. 



1938] REVISION OF THE GROUND SQUIRRELS 131 

Type. — None designated; Lyon and Osgood (1909, p. 169), list 
seven specimens in the United States National Museum collection as 
being the material used by Kennicott; no. xrWs: U. S. Natl. Mus., 
is hereby designated as lectotype ; 9 , skin and skull ; collected 50 
miles west of Fort Kearney, Nebr., August 9, 1857, by J. G. Cooper 
(orig. no. 44). 

Range. — Sandhill region of Nebraska; north to Todd County, 
S. Dak. ; east to Neligh, Nebr. ; south to Tuttle, Colo. ; west to Platte 
County, Wyo., and Greeley, Colo, (fig. 11). Zonal range: Upj)er 
Sonoran. 

Exter'nal characters. — Similar to C. s. major but averaging smaller ; 
dorsal spotting less distinct and tending to become obsolete, the 
white spots usually more distinctly edged with black; drab phase 
predominating. 

Cranial characters. — Skull similar to that of major but averaging 
smaller, with smaller audital bullae. 

Color. — Upper parts smoke gray, light drab, or avellaneous ; dorsal 
white spots of moderate size, but scattered and more or less indis- 
tinct, often nearly obsolete; most of the hairs on back tipped with 
black or fuscous black, these tips tending to form irregular and 
more or less indistinct spots, especially on hinder back; patch on 
front of face pinkish cinnamon or light vinaceous cinnamon; sides 
of nose and eye ring white ; sides of body washed with pale cartridge 
buff; front feet pinkish buff; hind feet whitish, washed with light 
pinkish cinnamon or cartridge buff; tail above, vinaceous fawn or 
wood brown, shaded on distal portion with fuscous and edged with 
cartridge buff; under parts white. 

Measurements. — Average of 10 adults (5 males, 5 females) from Nebraska: 
Total length, 214.3 (197-226) ; tail vertebrae, 64.B (56-79) ; hind foot, 31.8 
(30-34). Skull: Avei-age of 10 adults (5 males, 5 females) from Nebraska: 
Greatest length, 38.9 (37.7-39.9) ; palatilar length, 17.4 (16.5-18) ; zygomatic 
breadth, 23 (22.2-23.6) ; cranial breadth, 17.6 (17-18.2) ; interorbital breadth, 
7.8 (7-8.2) ; postorbital constriction, 13.2 (12.1-13.8) ; length of nasals, 13.3 
(12.5-13.9) ; maxillary tooth row, 7.2 (6.9^7.5). 

Remarks. — Kennicott recognized the near relationship of this form 
to C. s. spiloso7na when he described it in 1863. Not until recently, 
however, when large series of specimens from many localities have 
been obtained, has it become clear that it is connected with the more 
southern races by a nearly complete series of intergrades. 

/Specimens examined. — Total number, 33, as f oIIoavs : 

Colorado: Avalo (10 miles east, Logan County), 1; Greeley, 1; Merino (Logan 
County), 1;'" Sterling, 3; Tuttle (Kit Carson County), 1; Wmy, 2. 

Kansas: St. Francis (9 miles northwest), 1.^ 

Nebraska: Cherry County, 2; Fort Kearney (50 miles west), 1; Kennedy 
(Cherry County), 6; Lincoln County, 2; Neligh, 1; O'Fallons Bluff (Lincoln 
Coimty), 1; Simeon (Cherry County). 1; Valentine, 4. 

South Dakota: White River (south fork), 1. 

Wyoming: Little Bear Creek (20 miles southeast of Chugwater), 1; Wheat- 
land, 1; Fort Laramie (Goshen County), 1; Spoon Butte (Goshen County), 
1. 



•■"= Clevelanfl Mus. Nat. Hist. 
^Kansas Univ. Mus. Nat. Hist. 



132 NORTH AMERICAN FAUNA [No. 56 

CITELLUS PEROTENSIS (Mebeiam) 

Peeote Ground Squirrel 

(Pis. 25, D; 30, D) 

SpermopMlus perotensis Merriam, Biol. Soc. Wash. Proc. 8 : 131, Dec. 28, 1893. 
[Citellus] perotensis Elliot, Field Columb. Mus. Pub., Zool. Ser. .4: 145, 1904. 

Type. — Collected at Perote, Vera Cruz, Mexico, June 8, 1893, by 
E. W. Nelson and E. A. Goldman; female adult, skin and skull, no. 
54274, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 4976). 

Range. — Known only from the extreme eastern border of the 
Mexican tableland in the vicinity of Perote, Vera Cruz, at an alti- 
tude of 7,800 or 7,900 feet ; ranges to a point 10 miles south of Perote 
and eastward to within a few miles of Las Vigas (fig. 11). Zonal 
range: Upper Sonoran. 

External characters. — Similar to G. spilosoma pallescens but larger, 
with shorter tail; coloration more yellowish (less pinkish); dorsal 
spots buffy rather than white, smaller and less conspicuous (often 
nearly obsolete); under parts buffy instead of white; head marked 
with blackish. 

Cranial characters. — Skull similar to that of G. s. spilosoma but 
larger, with relatively narrower and higher brain case ; audital bullae 
broader and more flattened; molariform teeth heavier. 

Golor. — (Type, in worn pelage, June 8) : General tone of upper 
parts dull clay color, varied on hinder back with fuscous and very 
indistinctly speckled with pinkish buff ; top of head and face washed 
with fuscous black, sides of head washed with smoke gray; eyelids 
buffy white ; sides of body pinkish buff or cartridge buff ; under parts 
and feet similar or slightly paler; tail above, similar to the back, 
but distal two-thirds mixed with blackish and tipped with pale 
carti'idge buff ; tail beneath, pinkish buff, bordered at distal end with 
blackish. 

Variation. — Other specimens taken in June are considerably paler 
than the type, the general tone of upper parts varying from wood 
brown to drab, and some of the immature individuals are more con- 
spicuously spotted. 

Measurements. — Average of 11 adults from type locality: Total length, 250.4 
(243-261) ; tail vertebrae, 70.5 (57-78), hind foot, 38.7 (38-40). STcull: Great- 
est length, 43.5 (42.2^4.5) ; palatilar length, 20.6 (20-21.5) ; zygomatic breadth, 
26.4 (25.2-27.3) ; cranial breadth, 19.5 (19.1-20) ; interorbital breadth, 9.3 
(8.8-9.8) ; postorbital constriction, 14 (13.3-14.7) ; length of nasals, 15.5 
(14.5-16.5); maxillary tooth row, 8.7 (8.3-9). 

Remarks. — The Perote ground squirrel — the largest member of 
the spilosoma group — is clearly related to G. s. spilosonia but appar- 
ently does not intergrade with it. Its range apparently is restricted 
to the high plains at the extreme eastern border of the Mexican 
tableland. As pointed out by Merriam, this species bears a general 
external resemblance to G. richardsonii elegans^ but differs widely 
from it in skull characters and belongs in another subgenus. 

Specimens examined. — Total number, 16, from type locality. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



133 



POLIOCITELLUS, subgenus nov. 

[Characters and description on p. 42] 

CITELLUS FRANKLINII (Sabine) 

Fbanklin's Ground Squibbex 

(PI. 6) 

Arctomys franklinii Sabine, Linn. Soc. London Trans. 13: 587, 1822. 

Arctomys (Spermophilus) franklinii Richardson, Fauna Boreali-Amer. 1: 168, 

1829. 
Spermophilus franklini Lesson, Manual Mamm., p. 244, 1827. 
[Citellus] franklini Trouessart, Cat. Mamm., Sup., p. 342, 1904. 

Tyjje. — Collected at Carlton House, Saskatchewan, probably by 
John Eichardson (Preble, 1908, p. 165) ; male, skin and skull, no. 61a, 
British Museum. 

Range. — Great Plains region of southern Canada and the upper 
Mississippi and Missouri Valleys; north to Athabaska Landing, 
Alberta; east to Lake 
Winnipeg, Manitoba, 
southeastern Wiscon- 
sin, and northwestern 
Indiana; south to 
southeastern Kansas, 
central Missouri, and 
central Illinois; w^est 
to Edmonton, Alberta, 
the Missouri Valley in 
North Dakota and 
South Dakota, central 
Nebraska and central 
Kansas ; introduced in 
Ocean County, N. J. 
(fig. 12). Zonal 
range: Transition and 
Upper Austral. 

External c h ar ac- 
ters. — About the size 
of G. parryii plesius 
but tail longer ; 
ears larger, suborbicu- 
lar. 

Cranial characters. — Skull long and narrow, with flattened super- 
ior outline, quite unlike any member of the subgenus Citellus; some- 
what resembling G. heecheyi but rostrum longer ; brain case narrower 
and less inflated; temporal region more constricted; and anterior 
border of zygomatic notch reaching only to posterior border of m ^. 

Golor. — Summer pelage (topotypes, July) : Head grayish, the 
bases of the hairs fuscous black, tips grayish white. (The color tone 
of the head varies with the amount of wear, worn pelages being de- 
cidedly darker than fresh pelages because of the exposure of the 
dark bases of the hairs.) Dorsum tawny olive or clay color, more 
or less shaded with fuscous; sides pinkish buff or cinnamon buff 
mixed with grayish white; thighs pale smoke gray, shaded with 
pinkish buff and fuscous ; front feet pinkish buff ; hind feet grayish 





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FiQDHB 12. — Distribution of Citellus franklinii. 



J34 NORTH AMERICAN FAUNA [No. 56 

white, shaded with tilleul buff ; tail above and below, blackish mixed 
with tilleul buff, overlaid and bordered with creamy white; under 
parts pinkish buff or buffy white. 

Variation. — Certain specimens in worn summer pelage are de- 
cidedly darker above than those in the fresh pelage described, the 
general tone of the upper parts being sayal brown or ochraceous 
tawny; in these the exposure of the fuscous bases of the hairs pro- 
duces the effect of spotting. Winter pelage (North Dakota speci- 
mens in May) : Similar to fresh summer pelage but paler, the tips 
of the hairs on upper parts pinkish buff, the sides paler and more 
whitish; feet paler and less buffy. Specimens taken in April 
(Nebraska) and May (Alberta), being apparently in winter pelage, 
are darker than those described above, the general tone of the upper 
parts being clay color. 

Measurements.— AN&Yaige of 6 adult males from Saskatchewan (type locality) 
and Alberta: Total length, 388.7 (381-397); tail vertebrae, 144.7 (136-153); 
hind foot, 55.1 (53-57.5) ; ear from notch, 10.5 (10-11). Average of 5 adult 
females from Saskatchewan (Wingard and Indian Head) : Total length, 384.6 
(363-401) ; tail vertebrae, 146.8 (133-156) ; hind foot, 52.8 (51-55) ; ear from 
notch, 10.5 (10-11). Skull: Average of 5 adult males from Saskatchewan and 
Alberta: Greatest length, 54.2 (53-54.6) ; palatilar length, 26.3 (25-27) ; zygo- 
matic breadth, 31.4 (31-32.1) ; cranial breadth, 21.1 (20.9-21.3) ; interorbital 
breadth, 12.3 (12.1-12.7) ; postorbital constriction, 13.1 (12.8-13.4) ; length of 
nasals, 18.4 (17.6^18.8) ; maxillary tooth row, 10.3 (10.2-10.4). Average of 5 
adult females from Saskatchewan (Wingard and Indian Head) : Greatest length, 
53.2 (52.1-55.1) ; palatilar length, 25.8 (25-27) ; zygomatic breadth, 30.6 (30.1- 
31.4) ; cranial breadth, 20.5 (20.2-20.7) ; interorbital breadth, 12 (11.4-12.5) ; 
postorbital constriction, 13.1 (13-13.4) ; length of nasals, 18.4 (17.8-19.6) ; 
maxillary tooth row, 10.4 (10.2-10.7). 

Remarks. — Franklin's gi'ound squirrel is a very distinct species, 
having no close relatives and although it exhibits considerable varia- 
tion in color, these differences are individual and not correlated with 
geographical distribution. It was introduced into New Jersey at 
Tuckerton in May 1867, a single pair brought, from Illinois having 
escaped from their cage and established themselves in the sandy fields. 
Since then they have spread northward as far as Manahawken and 
westward to Speedwell (Stone, 1908, p, 80). 

Specimens examined. — Total number, 160, as follows : 

Alberta: Edmonton, 1; Sturgeon River (25 miles north of Edmonton), 2. 

Ilimois: West Northfield (Cook County), 1.'' 

Indiana: Benton County, 1; Lake Village (Newton County), 6; ^^ North Liberty 

(St. Joseph County), 3.'" 
Iowa: Ames, 2; Charles City, 1;=" Clay County, 9;'' Milford, 1;** Wall Lake, 

Kansas: Manhattan, 1; Onaga, 1. 

Manitoba: Carberry, 3; Manitoba House, 1; Winnipeg, 1. 

Minnesota : Browns Valley, 4 ; Cass Lake, 2 ; Elk River, 10 ; Fort Snelling, 1 ; ^' 

Heron Lake, 2; Ortonville, 10. 
Nebraska: Ames (Dodge County), 1; Columbus, 2; Kearney, 1; Niobrara, 1; 

Verdigris, 1. 
New Jersey: Tuckerton, 5. 
North Dakota: Blackmer (Richland County), 4; Devils Lake, 6; Pairmount 

14; Fargo, 1; Fish Lake (Benson County), 4; Grafton, 1; Grand Forks, 1 

Harwood (Cass County), 3; Kathryn (Barnes County), 1; La Moure, 1 



3* Univ. Michigan Mus. Zool. 
^ P. F. ETiekie collection. 
2' Univ. of Notre Dame, 
s^ Dayton Stoner collection. 
38 Field Mus. Nat. Hist. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



135 



Larimore, 2; Oakes, 3; Pembina, 5; Spring Lake (Rolette County), 1; 

Stump Lake, 2 ; Turtle Mountains, 2 ; ** Walhalla, 2. 
Ontario : Rainy River, 7/° 
Saskatchewan : Carlton, 4 ; Indian Head, 3 ; Oxbow, 1 ; Prince Albert, 1 ; ^ Win- 

gard, 5. 
South Dakota: Flandreau, 1; Fort Sisseton (Marshall County), 2; Scotland, 

1 ; Vermillion, 1. 
Wisconsin: Delavan, 4. 

Subgenus OTOSPERMOPHILUS Brandt 

[Characters on p. 43] 
COLOE PATTEHN 

In the typical species and its near relatives the color of the upper 
parts is a mixture of various shades of buif, black, and white, the 
hinder back usually presenting a mottled appearance; some races 
have prominent whitish shoulder patches, others have solid black 
areas on the head or anterior back ; the bases of the hairs are fuscous ; 
the tail hairs are banded with black. 



PBXAGE AND MOLT 



worn. 



The pelage is full and soft when fresh, shorter and harsher when 
There is but one molt annually, which may occur at any 
time from early in May to early in September, depending in part 
on the climate. Breeding females are likely to molt later than males. 



Key to Species and Subspecies 

^ Head black or brown. 

b.^ Shoulders and fore back solid black or brown huclcleyi 

b.^ Shoulders and fore back mixed with whitish, 
c* Upper parts brownish or huffy. 

d.} Size small (skull length less than 60 mm) atricapillus 

d.^ Size large(skull length more than 60 mm). 

f} Head black coucliii 

f.^ Head brown rupestris 

c.^ Upper I'.arts blackish varicyatufs 

- Head mixed with buffy. 
&.' Nape and shoulders with a dark median area. 

c.^ Fore back with a blackish patch douglusii 

c.^ Fore back without a blackish patch. 

d.^ White shoulder patches indistinct nesioticvs 

d." White shoulder patches distinct, 
e.' Upper parts darker. 

f} Feet wliitish sierrae 

f.^ Feet buffy. 

g} Under parts darker (more buffy) beecheyi ( 

(J.' Under parts paler (more whitish) nudipcs 

e.^ Upper parts paler. 

f} Size larger (skull length, 55-62 mm) fishcri 

f.^ Size smaller (skull length, 52-GO mm) parvulus 

b.^ Nape and shoulders without dark median area, 
c* Upper parts blackish. 

d.^ Head more blackish rariegattis 

d.' Head more buffy tularosac 

c? Upper parts brownish or buffy. 

d} Size smaller (skull length of 9 less than 57 mm) rnpinarnm 

d.' Size larger (skull length of 9 more than 57 mm). 

f.' Hinder back more tawny utah 

f.^ Hinder back more buffy grammnrus 



p. 141). 



p. 161). 



P- 



130). 
138). 
136). 



150). 
160). 



p. 153). 



14S). 
158). 

154). 
156). 



136). 
145). 



p. 159). 



146). 
142). 



** Univ. Michigan Mus. Zool. 
»« Field Mus. Nat. Hist. 
*• Royal Ontario Mus. 



236 NORTH AMERICAN FAUNA [No. 56 

CITELLUS VARIEGATUS (Eexleben) 
[Synonymy under subspecies] 

Speciiic characters. — Size large; hind foot, 53-65 mm; tail, 174- 
263; skull length, 56-67.7. Skull somewhat resembling that of 
C. parryii but differing in the characters of the subgenus ; dorsal pro- 
file nearly flat ; brain case and interorbital region relatively broader ; 
parietal ridges meeting at posterior end of cranium to form a slight 
crest ; rostrum relatively broad, tapering gradually ; postorbital proc- 
esses stout, decurved; supraorbital borders of frontals slightly ele- 
vated ; zygomata less widely expanded ; audital bullae relatively long 
and narrow, the meatus tube very short; upper incisors stout, not 
prognathous; molariform teeth low-crowned (as described under 
subgeneric characters, p. 43). 

Color. — Head varying from pinkish buff or pinkish cinnamon to 
seal brown and fuscous black; upper parts varying from grayish 
white mixed with cinnamon buff to snuff brown, mikado brown, bone 
brown, and dark blackish brown; in some races the head and fore 
back, in others the whole dorsal surface is blackish ; the tail is mixed 
black or brown and buffy white. 

CITELLUS VARIEGATUS VARIEGATUS (Ebxleben) 

Mexican Rock Sqtjierei, 

(PI. 7) 

[Sciurusi variegatus Erxleben, Syst Regni, Anim 1 : 421, 1777. 

Sciurus huccatus Lichtenstein, Abhandl. k. Akad. Wiss. Berlin, 1827 (1830), 
p. 117. 

Spermophilus macrourus Bennett, Zool. Soc. London Proc. 1833; 41. ("West- 
Mexico" — in Zool. Society register.) 

Spermophilus variegatus Nelson, Science (n. s.) 8: 898, 1898. 

[Citellus] variegatus Elliot, Field Columb. Mus. Pub., Zool. Ser. 4 : 148, 1904. 

Otospermophilus variegatus Miller, U. S. Natl. Mus. Bull. 128: 181, 1924. 

Type. — None designated; type locality fixed at Valley of Mexico 
near the City of Mexico (Nelson, 1898, p. 898) . 

Range. — (I^entral Mexico, from southern Zacatecas and San Luis 
Potosi south to Michoacan and the Valley of Mexico ; west to Colima, 
Jalisco, and Nayarit (fig. 13). Zonal range: Upper and Lower 
Sonoran. 

External characters. — Size large; tail long (nearly half the total 
length) ; head blackish, more or less mixed with buff; general tone 
of upper parts gray, more or less heavily mixed with blackish ; tail 
mixed black and white. 

Cranial characters.— ^]sxi\\ of large size; zygomata heavy and 
rather widely expanded ; interorbital region broad ; postorbital proc- 
esses heavy ; nasals ending posteriorly on a line with ascending arms 
of premaxillae or slightly beyond. 

Color. — Winter pelage (Valley of Mexico) : Sides of nose pinkish 
buff or tilleul buff; front and sides of face brownish, mixed with 
buffy white; eyelids broadly margined with dull white; crown and 
occiput dark blackish brown ; hairs on the dorsal surface fuscous or 
fuscous black at base, banded with dull white or pinkish buff, some 
tipped with blackish; feet drab gray, tinged with fuscous; thighs 
washed with cinnamon buff or ochraceous tawny; tail blackish, 
mixed with buffy white and cinnamon buff; under parts grayish 
white or cinnamon buff. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



137 



Variation. — The majority of the specimens of this race have more 
or less black on the head* some however, have the hairs on the head 
fuscous basally , tipped with pinkish buff ; the amount of black show- 
ing on the dorsal surface varies considerably'^, some being only 
slightly darker than certain specimens of G. v. grammurus. 

Molt. — The molting season covers a considerable part of the year ; 
in a specimen from Nayarit, taken April 12, new pelage covers the 
head and anterior 
half of the back ; one 
from Guanajuato, 
June 20, and one 
from Michoacan, 
July 14, have nearly 
completed the molt; 
several from San 
Luis Potosi, August 
17, are badly worn 
and new pelage is 
coming in on the an- 
terior upper parts ; 
one from Guanajua- 
to, November 7, had 
acquired a fresh pel- 
age on the head and 
the posterior half of 
the body, leaving a 
worn area of old pel- 
age on the shoulders 
and nape. 

Measurements.— Kvev- 
age of 8 adult males 
from central Mexico 
(Federal District, Pueb- 
la, and Michoacan) : To- 
tal length. 499 (470- 
f)20) ; tail vertebrae, 
227.4 (197-249) ; hind 
foot, 62.7 (5^-65) ; ear 
from notch (dry), 18.9 
(18-20). Average of 7 
adult females from same 
region : Total length, 479 
(447-510) ; tall vertebrae, 222 (212-233) ; hind foot, 60 (57-64) ; ear from notch, 
19.2 (19-19.5, two specimens only) . Skull: Average of 9 adult males from central 
Mexico (Federal District, Puebla, Michoacan, Jalisco, San Luis Potosi, and Co- 
lima) : Greatest length, 65.0 (64.1-67.7) ; palatilar length, 31.5 (29.8-33) ; zygo- 
matic breadth, 40.5 (38.1-41.8) ; cranial breadth, 26.1 (25.5-26.6) ; interorbital 
breadth, 16.9 (15.5-18.1) ; postorbital constriction, 17.7 (16.7-18.8) ; length of 
nasals, 23.8 (22.4-24.5) ; maxillary tooth row, 13.4 (12.8-14). Average of 7 
adult females from the same region: Greatest length, 62.1 (59-65.7) ; palatilar 
length, 29 (28.5-32.5) ; zygomatic breadth, 38.7 (36-42.4) ; cranial brcadtli, 25.5 
(24.3-26.7) ; interorbital breadth, 15.7 (13.7-18.8) ; postorbital constriction, 17.9 
(16.4-19.6) ; length of nasals, 21.8 (21-22.9) ; maxillary tooth row, 13.1 (12.7-13.7) . 

Remarks. —Poison (1898, p. 898) has shown the pertinence of Erx- 
leben's name Sciurus variegatus to the Mexican rock squirrel, and as 
suggested by him, this animal proves to be connected subspecifically 
with G. V. couchii and G. v. grammurus, as well as with G. v. rwpestris. 




FiGDRB 13. — Distribution of Citellus atricapillus and of the 
sub.ipecies of C. variegatus: 1, C. v. grammurua; 2, C. v. 
Utah; 3, O. v. tularosae; 4, O. v. huckleyi; 5, O. v. couchii; 
6, C. V. rupeatris; 7, C. v. variegatus; 8, C. atricapillus. 



J38 NORTH AMERICAN FAUNA [No. 56 

The subspecies is abundant over a large area in south-central 
Mexico. Specimens from Hacienda La Parada, Villar, and Rio 
Verde, in the State of San Luis Potosi, show approach to couchii in 
the darkening of the heads and paling of the backs; their skulls, 
however, agree well with those of variegatus and are distinctly larger 
than those of couchii. 

Specimens examined. — Total number, 95, as follows : 

Colima: Hacienda San Antonio (at base of Volcano of Colima) , 3. 

Guanajuato: Santa Rosa, 2; Silao, 1. 

Hidalgo: Encarnacion, 2; Ixmiquilpan, 2; Tulancingo, 1; Zimapan, 1. 

Jalisco: Ameca, 1; Atemajac, 9; Barranca Ibarra, 1; Chapala, 1; Etzatlan, 3; 

Guadalajara, 1 ; La Barca, 1 ; Lagos, 2 ; Ocotlan, 2 ; Plantinar, 1 ; Sierra 

Nevada de Colima, 1 ; Zacoalco, 1 ; Zapotlau, 6. 
Mexico : Mount Popocatapetl, 1 ; Amecameca, 1 ; Tlalpam, 6. 
Michoacan : Acambaro, 1 ; Los Reyes, 1 ; Mount Tancitaro, 2 ; Patzcuaro, 12 ; 

Querendaro, 1 ; Zamora, 2. 
Morelos: Tetela del Volcan, 1. 
Nayarit: Tepic, 1. 
Puebla: San Martin, 1. 
Queretaro: Tequisquiapan, 1. 
San Luis Potosi: Ahualulco, 1; Hacienda La Parada (20 miles northwest of 

San Luis Potosi), 12; Jesus Maria, 1; Rio Verde, 2; Villar, 5. 
Zacatecas: Berriozabal, 1. 

CITELLUS VARIEGATUS RUPESTRIS Allen 

Beown-headed Rock Squierel 

(Pis. 26, C; 31, C) 

Citellus (OtospermopliUus) grammurus rupestris Allen, Amer. Mus. Nat. Hist. 

Bull. 19: 595, Nov. 12, 1903. 
[Citellus varieciatus^ rupestris Elliot, Field Columb. Mus. Pub., Zool. Ser. 4: 

150, 1904. 
OtospermopliUus grammurus rupestris Miller, U. S. Natl. Mus. Bull. 128: 

181, 1924. 

Type. — Collected on Rio Sestin, northwestern Durango, Mexico, 
April 12, 1903, by J. H. Batty; female adult, skin and skull, no. 
21231, Amer. Mus. Nat. Hist. (orig. no. 419). 

Range. — Eastern and western slopes of tlie Sierra Madre and ad- 
jacent plains on eastern side from southern Durango north to south- 
ern Chihuahua; east to Chihuahua City and Santa Rosalia; west to 
Sierra de Choix, Sinaloa (fig. 13). Zonal range: Upper and Lower 
Sonoran and Transition. 

External characters. — Similar to C. v. variegatus., but upper parts 
decidedly paler and brownish or buffy rather than blackish in tone ; 
head brown instead of black ; under parts more buffy ; similar also to 
G. V. couchii but paler and less blackish in general tone, and head 
brown instead of black. 

Cranial characters. — Skull similar to that of variegatus and couchii., 
but averaging longer and relatively narrower, with longer nasals. 

Color. — (Topotypes in April) : Top and sides of head, nape, and 
ears, bone brown; front and sides of face more or less washed with 
buffy white ; eye ring whitish or buffy ; hairs on dorsal area fuscous at 
base, shading to bone brown on the nape and to hair brown on the 
rump and sides ; subterminal band of dorsal hairs varying from buffy 
white to cinnamon buff ; tips of hairs brown or fuscous ; tail above and 
below, buffy white, mixed with fuscous and sometimes also with 



1938] REVISION OF THE GROUND SQUIRRELS 139 

light cinnamon buff ; feet tilleul buff or pinkish buff, the legs washed 
with cinnamon buff or ochraceous tawny ; under parts varying from 
cinnamon buff to buffy white. 

Variation. — The topotype series shows a large amount of variation 
in color in the upper parts, apparently due in part to fading and wear 
of the pelage. The general tone of the dorsal surface varies from bone 
brown to cartridge buff or cinnamon buff; in a specimen from near 
Guadalupe y Calvo, Chihuahua, and one from Sierra de Choix, Sin- 
aloa, the brown of the head and nape extends to or beyond the middle 
of the back. 

Molt. — Many of the specimens from Eio Sestin, taken in April, are 
badly worn; two (Apr. 12, 17) show new pelage coming in on the 
anterior half of the back. 

Measurements. — Average of 9 adult males from tyne locality (Allen, 19n3b, 
p. 596) : Total length, 503 (451-540) ; tail vertebrae, 233 (210-^248) ; hind foot 
(without claws), 56.7 (55.5-57) ; ear from notch (dry), 26.3 (25-28). Fourteen 
adult females: Total length, 499 (463-521) ; tail vertebrae, 227 (203-241) ; hind 
foot, 56 (54-60) ; ear, 26.3 (25-29). The hind foot, as measured dry from 7 of 
these specimens (5 males; 2 females) averages 61.1 (59-65). One aclult male 
from Durango City: 510; 238; 60; one adult female from Guazamota, Durango : 
548; 263; 60. ^kull: Average of 7 adults (2 males, 5 females) from tvpe local- 
ity: Greatest length, 64 (61.2r-67) ; palatilar length, .30.6 (29-32.5) ; zygomatic 
breadth, 38.8 (37.5-40.9) ; cranial breadth, 25.3 (24.6-25.9) ; interorbital breadth, 
15.2 (14.6-16) ; postorbital constriction, 17.2 (15..5-18.1) ; length of nasals, 23.3 
(22.&-23.7) ; maxillary tooth row, 12.8 (11.9-13.3). 

Remarks. — This is a well-marked race, occupying an extensive area 
in western Mexico. Intergradation with C. v. grammurus is shown 
by series from Chihuahua and Santa Rosalia; most of the specimens 
from those localities have the head partly brownish black and agree 
generally in color with rupestris, though two adults from Chi- 
huahua and three young from Santa Rosalia are scarcely different 
from typical specimens of grammurus. The skulls are likewise inter- 
mediate in characters, resembling those of rupestris in shape, though 
smaller, and having larger molars than grammurus. 

A single specimen from Guazamota, southern Durango, which 
agrees in color with riipestns., has a skull agreeing in size and shape 
with skulls of variegatus. 

No intergrades of this race with couchii have been seen, but quite 
likely such may be found when collections are secured from the terri- 
tory intervening between their known ranges. 

Specimens examined — Total number, 58, as follows: 

Chihuahua: Chihuahua, 9; Samachique (Sierra Tarahumara), 4;" Santa 

Rosalia, 7; Sierra Madre, near Guadalupe y Calvo, 4. 
Durango: Coyotes, 3;*^ Durango, 1; Guazamota, 1; Rancho Bailon (east of 

Sestin Valley), 10;" Rio Sestin, 17. 
Sinaloa: Sierra de Choix (50 miles northeast of Choix), 1. 
Sonora: Oposura, 1. 

CITELLUS VARIEGATUS COUCHII (Baird) 

Couch's Rock Squirrel 

SpermopJiilus couchii Baird, Acad. Nat. Sci. Phila. Proc. 1855 : 332. 
S[permophilus] grammurus couchii Allen, Amer. Mus. Nat. Hist. Bull. 8: 68, 1896 

^^Amer. Mus. Nat. Hist. 
*i Field Mus. Nat. Hist. 



140 NORTH AMERICAN FAUNA [No. 56 

Citellus variegatus couchi Bailey, North Amer. Fauna 25 : 83, 1905. 
OtospermopMlus grammurus couchii Mearns, U. S. Natl. Mus. Bull. 56: 324, 1907. 

Type. — Collected at Santa Catarina (a few miles west of Mon- 
terey) , Nuevo Leon, Mexico, April 1853, by Lt. D. N. Couch; skin and 
skull, no. i3^ U. S. Natl. Mus. 

Range. — Northeastern Mexico, from southern Coahuila and Nuevo 
Leon north to the Chisos Mountains, Tex. (fig. 13). Zonal range: 
Upper and Lower Sonoran. 

External characters. — Similar to G. v. variegatus but smaller ; dor- 
sum paler and more brownish or buffy (less blackish); feet paler; 
top of head always black or dark brown. Similar to G. v. rupestris 
but head and upper parts darker and more blackish (less brownish or 
buffy) ; under parts darker. 

Granial characters. — Skull similar to that of variegatus but aver- 
aging smaller, especially in the males. 

Golor. — (Specimens in normal phase from Saltillo, Coahuila) : 
Front and sides of face grayish, with a tinge of brown ; crown, occi- 
put, sides of head, and ears, dark seal brown or black ; eyelids broadly 
margined above and below with grayish white; hairs on dorsal area 
fuscous at base, tipped with white on nape and shoulders, and with 
pinkish buff on middle and hinder back ; middle of back often show- 
ing a brownish patch. 

Variation. — Of eight specimens collected at the type locality, only 
one is of the normal color, the other seven being melanistic ; in these 
the head and upper parts are dark blackish brown, shading on hinder 
back to dark seal brown; feet and under parts seal brown; tail seal 
brown, shaded with blackish brown. In faded pelage these melanistic 
specimens show patches of cinnamon or walnut brown on the back. 

Molt. — Specimens taken at the type locality on April 13 show the 
molt in progress, the greater part of the body having acquired a new 
coat, while patches of the old faded pelage still remain on the rump 
and hinder back. 

Measurements. — ^Average of 15 adults (9 males, 6 females) from Santa Cata- 
rina and Saltillo, Mexico: Total length, 466 (430-493); tail vertebrae, 204 
(174-235) ; hind foot, 60.9 (58-64). Skull: Average of 16 adults (8 males, 8 
females) from the same localities: Greatest length, 60.1 (57-63.6); palatilar 
length, 28.6 (26-30.5) ; zygomatic breadth, 37.4 (34-39.3) ; cranial breadth, 24.7 
(23.5r-25.5) ; interorbital breadth, 15 (12.3-17.4) ; postorbital constriction, 17 
(15.9-18.1) ; length of nasals, 20.4 (18.5-21.9) ; maxillary tooth row, 12.4 
(11.8-13). 

Remarks. — This race is closely related to variegatus and furnishes 
a link connecting the latter with G. v. grammurus. In the typical 
form, as found in Coahuila and Nuevo Leon, it is distinguished by 
the combination of a blackish or brownish head, sharply contrasted 
with a rather pale-colored back. 

Writing of these squirrels as seen at Santa Catarina, Nuevo Leon, 
Nelson (ms, notes) says: 

Although the bare sun-baked limestone slopes of the canyons where they 
live are practically devoid of any cover formed by vegetation and the rocks 
are pale gray, so that these animals live in a glare of intense light, yet at 
least 80 percent of those seen were melanistic. These black animals sunning 
themselves on the pale-colored rocks were very conspicuous. 

At Saltillo, Coahuila, where 12 specimens were taken, no black 
ones were seen, but in the canyons of the Sierra Guadalupe more than 
half of the animals seen were in the melanistic phase. 



1938] REVISION OF THE GROUND SQUIRRELS 141 

Four specimens from the Chisos Mountains, Tex., are best referred 
to this race, although two of them show apparent intergradation 
with grammurus in ha\dng the heads partly gray rather than solid 
black ; one of the black-headed ones has the black color reaching to 
the middle of the back, as in C. v. huckleyi. The skulls agree closely 
with those of typical G. v. couchii. One specimen from Boquillas, 
Tex., in the melanistic phase is wholly seal brown. 

Specimens examined. — Total number, 29, as follows : 

Coahuila: Carneros, 1; Saltillo, 12; Sierra Encarnacion, 1; Sierra Guadalupe. 1. 

Nuevo Leon: Santa Catarina, 8. 

Tamaulipas: Victoria, 1. 

Texas : Boquillas, 1 ; Chisos Mountains, 4. 

CITELLUS VARIEGATUS BUCKLEYI (Sr^vcK) 

Blvck-backed Rock Squikbei. 

(PI. 7) 

Spermophilus ImckJeyi Slack, Acad. Nat. Sci. Phila. Proc. 1861: 314. 
Spermophilus grammurus buckleyi Allen, Amer. Mus. Nat Hist. Bull. 8: 67, 

1896. 
Citellus variegatus "buckleyi Bailey, North Amer. Fauna 25: 84, 1905. 
Otospermophilua grammurus buckleyi Mearns, U. S. Natl. Mus. Bull. 56: 323, 

1907. 

Type. — Collected at Packsaddle Mountain, Llano County, Tex., 
about 1861 by S. R. Buckley ; entered as no. 998, Museum Acad. Nat. 
Sci., Philadelphia, but now reported missing. 

Range. — South-central Texas, "in the rough and semiarid mesquite 
country along the eastern slope of the southern arm of the Staked 
Plains' (Bailey, 1905, p. 84), from the upper Nueces River (Rock- 
springs) east nearly to San Antonio and Austin; north to San Saba 
River (fig. 13). Zonal range: Upper and Lower Sonoran. 

External characters. — Similar to C. v. couchii but upper parts more 
extensively blackish. 

Cranial characters. — Skull similar to that of couchii^ but averaging 
larger, with longer nasals; shorter and relatively broader than that 
of C. V. rupestris, with smaller molariform teeth. 

Color. — Head and anterior upper parts, to or beyond the middle 
of the back, black or dark seal brown, sometimes sparingly sprinkled 
with whitish hairs, especially along the sides ; hinder back and sides 
grizzled iron gray, the bases of the hairs fuscous, tipped with white 
or pale buff ; feet drab gray, more or less washed with fuscous ; tail 
fuscous black, variegated and tipped with pale buffy white ; under 
parts fuscous, more or less shaded with white and pinkish buff. 

Variation. — Wholly black individuals of this race have not been 
seen; one from Japonica, Tex., however, has the black extending 
along the back from nose to root of tail with a considerable mixture 
of whitish hairs along the sides; a juvenile specimen from Llano 
has the crown black, but the rest of the body grizzled gray. 

Molt. — Two specimens from Llano, taken May 12 and 13, sliow 
the molt in progress, fresh pelage covering the anterior part of the 
body to beyond the middle of the back. One from Japonica, taken 
July 7, shows fresh pelage covering nearly the whole body except a 
small strip across the middle of the back, where the old faded pelage 
still remains. 



142 NORTH AMERICAN FAUNA [No. 56 

Measurements. — Average of 11 adults (5 males, 6 females) from central 
Texas (Llano, Japonica, Rocksprlngs, Camp Verde) : Total length, 500 (470- 
525) ; tail vertebrae, 226 (210-252) ; hind foot, 62 (60-65) ; ear from notch 
(dry), 19.7 (19-22). SJadl: Average of 15 adults (6 males, 9 females), from 
Mason and Llano, Tex.: Greatest length, 62.9 (60.6-64.8); palatilar length. 
29.8 (28.5-31) ; zygomatic breadth, 38.3 (36.4-40.2) ; cranial breadth, 25.1 (24.7- 
26.3) ; interorbital breadth, 14.5 (13.7-15.9) ; postorbital constriction, 17.7 
(16.5-18.4) ; length of nasals, 23.6 (21.5-24.8) ; maxillary tooth rovp, 12.2 
(11.5-13). 

Remarks. — This race occupies a small area at the eastern edge of 
the range of the species in Texas; it has developed large size and 
extensively blackish coloration. Apparently it intergrades with G. v. 
grammuriis in the region between the mouths of Pecos and Devils 
Rivers, the specimens from that section being referred to grammurus. 
Bailey (1905, p. 84), however, states: 

Apparently the open divide between the headwaters of the Nueces and the 
headwaters of the streams flowing into the Rio Grande separates the ranges of 
buckJeyl and coiichi [here referred to grammurus] with a neutral strip in 
which neither occurs. 

He adds (ms. notes) : 

I see no way to account for the peculiar coloration of this squirrel on the 
grounds of protective coloration. There are few if any dark colored rocks or 
burnt logs and trees [in its habitat]. The rocks are mainly light colored 
granite. 

Specimens examined. — Total number, 42, as follows: 

Texas: Austin (16 miles northwest), 1; Bull Creek (Travis County), 1; 
Camp Verde (7 miles west, Kerr County), 3; Fort Mason, 1; Ingram (Kerr 
County), 3;*" Japonica (Kerr County), 1; Llano, 11; Mason, 18; Rock- 
springs, 3. 

CITELLUS VARIEGATUS GRAMMURUS (Say) 
Say's Rock Squierel 

Siciurusi f/rammurus Say, Long's Exped. Rocky Mountains 2: 72, 1823. 

[Spermophilus grammurus^ var. grammurus Allen. Boston Soc. Nat. Hist. Proc. 
16: 293, 1874. 

Anisonyx {Otospermophilus) grammurus Allen, Amer. Mus. Nat. Hist. Bull. 7: 
237, 1895. 

[Citellus variegattis] grammurus Elliot, Field Columb. Mus. Pub., Zool. Ser. 4: 
149, 1904. 

Otospermophilus grammurus Mearns, U. S. Natl. Mus. Bull. 56: 315, 1907. 

Citellus grammurus grammurus Miller, U. S. Natl. Mus. Bull. 79: 208, 1912. 

Citellus variegatus juglans Bailey, Biol. Soc. Wash. Proc. 26: 131, 1913 (Glen- 
wood, N. Mex.). 

Otospermophilus grammurus grammurus Miller, U. S. Natl. Mus. Bull. 128: 180, 
1924. 

Type. — None designated ; specimen on which Say's description was 
based was taken on Purgatory River, near mouth of Chacuaco Creek, 
Las Animas County, Colo. (Cary 1911, p. 87). 

Range. — Mountain valleys and foothills in Colorado, New Mexico, 
Arizona, southeastern and southwestern Utah, southern Nevada, 
northwestern Chihuahua, and eastern Sonora ; north to eastern Lari- 
mer County, Colo,; east to Baca County, Colo.; south to southern 
Texas (Eagle Pass), and southern Sonora; west to the Providence 
Mountains, Calif., and Charleston Mountains, Nev. (fig. 13). Zonal 

*2 Cleveland Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 143 

'lange: Upper Sonoran and Transition (4,200-8,500 feet in New 
Mexico). 

External characters. — Similar to C. v. couchii but much paler, and 
head without any black. 

Cranial characters. — Skull very similar to that of couchii but 
averaging slightly shorter, though of the same breadth ; nasals longer, 
projecting slightly beyond the posterior ends of the premaxillae; 
niolariform teeth smaller. 

Color. — (April specimen in unworn pelage, 18 miles south of 
La Junta, Colo.) : Head and occiput pinkish buff, faintly shaded with 
fuscous; sides of nose cartridge buff; ej^e ring white; fore part of 
back, shoulders, and sides grayish white, slightly mixed with brown- 
ish ; hinder part of back and rump cinnamon buff, moderately varied 
with clove brown; bases of hairs on dorsal area clove brown; ears 
hair brown, shaded with pinkish buff; front legs buffy white; hind 
legs cinnamon buff; fore and hind feet cartridge buff; tail mixed 
pinkish buff and bone brown, edged with grayish white; under parts 
buffy white, shaded with pinkish buff. 

Variation. — September specimens from Bear Canyon, N, Mex., 
(about 12 miles northeast of Raton) and others from various parts of 
the range of the subspecies are considerably darker than the April 
specimens described above ; the middle and hinder back pinkish cinna- 
mon, heavily washed with brown (the general tone about cinnamon 
brown) ; head pinkish cinnamon more or less shaded with brown ; 
sides of nose pinkish buff; ears clove brown outside, wood brown in- 
side; feet pinkisli buff or cinnamon buff; tail mixed black and buffy 
white; edged with grayish white. Occasional specimens (Fort Hua- 
chuca and Graham Mountains, Ariz.) have the back clear grayish, 
with only a very slight wash of buff. 

Molt. — There is normally but one molt annually, in July or August. 
Two specimens (male and female) taken at San Pedro, N. Mex., July 
5 and 6, show new pelage covering the anterior half of the body, the 
posterior half being badly worn. An adult female from Big Sandy 
Creek. Ariz., July 21, shows a similar progress of the molt. An adult 
male from Sierra Grande, N. Mex., August 19, is molting irregularly 
on the dorsal surface. An adult female from Red Lake, Ariz., Sep- 
tember 7, is badly worn on the anterior half of the body and has the 
posterior portion covered with a fresh, full pelage. 

As the season advances the pelage usually becomes paler and more 
grayish, due apparently to wearing off of the buffy tips to the hairs 
of the dorsal area. 

Measurements. — Average of 11 adults (3 males, 8 females) from southeastern 
Colorado (La Junta, Trinidad, Canon City) : Total length, 467.7 (434-510) ; 
tail vertebrae, 210.3 (19S-235) ; hind foot, 57 (53-GO) ; ear from notch (dry), 17 
(15-19) ; average of 10 adults (4 males, 6 females) from southeastern Arizona 
(Fort Huachuca, Oracle, Santa Catalina Mountains): 477; 204; 58; 19.5. 
Skull: Average of 6 adult males from northeastern New Mexico (Polsom, Chico 
Springs, Sierra Grande) and Trinidad, Colo.: Greatest length, G0.9 (58.8-63.5) ; 
palatilar length, 29.3 (28.5-30); zvgomntic breadth, 37.9 (30.4-39.1); cranial 
breadth, 25 (24.1-25.7) ; interorbital breadth, 14.S (13.5-15.8) ; postorbital con- 
striction, 17.6 (16.8-18.6) ; length of nasals, 21.9 (20.6-23) ; maxillary tooth row, 
11.7 (11.3-12). Average of 10 adult females from southeastern Colorado (Trini- 
dad, La .lunta. Canon City) and northeastern New Mexico (Clayton, Bear Can- 
yon) : Greatest length, 59.7 (57.8-62.7) ; palatilar length, 28.5 (26.8-29.7) ; zygo- 
matic breadth, 36.6 (34-38.9) ; cranial breadth, 24.9 (24.1-25.6) ; interorbital 
breadth, 14.7 (13.5-15.6); postorbital constriction, 17.4 (16.2-18.2); length of 



l^ NORTH AMERICAN FAUNA [No. 56 

nasals, 21.1 (20-22.3); maxillary tooth row, 11.8 (11.3-12.3). Average of 12 
adult females from Fort Huachuca, Ariz.: 60.5; 29.2; 37.1; 25.3; 14.8; 18; 
21.8; 11.8. 

Remarks. — Say's rock squirrel has a very wide range and is sub- 
ject to great individual and seasonal variation. No appreciable 
departure from the typical coloration is found in the large series 
examined from New Mexico and Arizona, including the form ^^jug- 
lans" named by Bailey from Glenwood, N. Mex. 

A series of 10 specimens from the Davis Mountains, Tex., shows 
approach to couchii in the darkening of the heads of about half of 
the series; only one individual, however, has a wholly black head. 
The skulls average somewhat larger than those of either grammurus 
or couchii^ being in fact, about the size of those of O. v. tuehleyi. 

A series of 15 specimens from the Rio Grande, between the Pecos 
River and Devils River, shows intergradation with liucMeyi in par- 
tial darkening of the heads and shoulders of 5 individuals, the ma- 
jority being almost typical of grammurus. Skulls of two of the 
specimens are larger even than those of huokleyi^ while those of three 
other adults are typical of grammurus. 

Specimens from Colonia Garcia, Chihuahua, and from numerous 
localities in Sonora as far south as Camoa, on the Rio Mayo, are 
only slightly darker than typical grammurus. One from Oposura 
and one from Ortiz, however, have considerable black on the nape 
and shoulders, thus showing approach to G. v. rupestris; the skulls 
of all of these from Chihuahua and Sonora agree closely with typ- 
ical grammurus and do not approach rupestris in any characters. 

This race intergrades with the subspecies utah in southwestern 
and probably in eastern Utah; the few specimens examined from 
western Colorado appear to be typical grammurus. 

There is no indication that this species intergrades with heecheyi, 
specimens from the Providence Mountains, Calif., being typical 
grammurus. 

Specimens examined. — Total number, 437, as follows : 

Arizona: Anderson Mesa (Coconino County), 1; Apache (Cochise County), 2; 
Apache Maid Mountain (Coconino County), 2; Baker Butte (Coconino 
County), 2; Bates Well (20 miles south of Ajo, Pima County), 1; Beale 
Spring (near Kingman, Mohave County), 1; Big Sandy Creek (near Owens, 
Mohave County), 2; Bill WUliams Mountain, 1; Bisbee, 1; Black River 
(5 miles above mouth of White River), 1; Blue River (Cosper Ranch, 
Greenlee County), 3; Calabasas (Santa Cruz County), 4; Chiricahua 
Ranch (San Carlos Indian Reservation, Graham County), 1; Chiricahua 
Mountains, 2; Crown King (Yavapai County), 1; Congress Junction 
(Yavapai County), 1; Camp Verde (Yavapai County), 2; Dos Cabezos 
(Cochise County), 1; Fish Creek (Tonto National Forest, Maricopa 
County), 1; Fort Bowie (Cochise County), 2; Fort Grant (Graham 
County), 3; Fort Huachuca, 30; Fort Lowell, 1; Fort Whipple (Yavapai 
County), 1; Galiuro Mountains (Graham County), 1; Graham Mountains, 
12; Grand Canyon (Coconino Plateau), 8; Huachuca Mountains, 12; 
Hualpai Mountains, 9; Keams Canyon (Navajo County), 1; Kingman, 1;'^ 
Kirkland (Yavapai County), 1; La Osa (Pima County), 1; Mayer (Ya- 
vapai County), 2; Mineral Park (Mohave County), 2; Montezuma Well 
(near Camp Verde, Yavapai County), 4; Mowry (Patagonia Mountains), 
1; Nantan Plateau (San Carlos Indian Reservation), 3; Nogales, 2; 
Oatman, 1;" Oracle (Pinal County), 15; Oak Creek (15 miles southwest 
of Flagstaff), 2; Patagonia Mountains, 5; Payson (Gila County), 1; 
Phantom Ranch (Grand Canj^on), 2; Pine Spring (8 miles north, Hualpai 

*' Univ. Michigan Mus. Zool. 
« Cleveland Mus. Nat. Hist. 



19381 REVISION OF THE GROUND SQUIRRELS 145 

Indian Reservation), 1; Portal (Cochise County), 2; Prescott, 3; Prieto 
Plateau (east fork Eagle Creek, Greenlee County), 1; Red Lake (Coconino 
County), 2; Rice (Gila County), 1; Roosevelt (Gila County), 2; San 
Bernardino Ranch (Mexican boundary), 2; San Francisco Mountain, 3; 
Santa Cataliua Mountains, 2; Santa Cruz River (near Monument 118), 
2 ; Santa Rita Mountains, 3 ; Sierra Ancha Mountains, 2 ; Simmons 
(Yavapai County), 1; Springerville, 2; Trumbull Mountains (Mohave 
County), 5; Tubac, 1; Tucson Mountains, 1; Vicksburg (Yuma County), 
1; Warsaw Mills (Pajaritos Mountains, near Monument 132), 4; White- 
river (10 miles north, Navajo County), 1. 

California: Providence Mountains, 10. 

Chihuahua: Colonia Garcia, 5; San Luis Mountains, 4. 

Colorado: Ashbaugh's Ranch, Montezuma County, 1; Boulder, 2; Buena Vista, 
1 ; Canon City, 6 ; Chaffee County, 2 ; " Grand Junction, 1 ; La Junta (18 
miles south), 3; La Veta, 1;*^ Lyons, 1; Piuewood (Larimer County), 1; 
Plateau Creek (12 miles east of Tunnel, Mesa County), 1; Rifle, 1; 
Trinidad, 7. 

Nevada: Cedar Basin (Clark County), 4;** Charleston Mountains, 11;** Sheep 
Mountains (Clark County), 1/^ 

New Mexico: Animas Mountains, 2; Apache (Grant County), 3; Arroyo Seco 
(Taos County), 1; Bear Canyon (5 miles northeast of Bell, Colfax 
County), 3; Burro Mountains (Grant County), 3; Capitan Mountains, 16; 
Carlsbad, 2; Carlsbad Cave, 1; Carrizozo (14 miles north), 1;" Chico 
(CoLfax County), 1; Cienequilla (10 miles southwest of Taos), 4; Clayton, 
3; Cloverdale, 1; Copperton (south of Mt. Sedgwick, Valencia County), 
1; Florida Mountains (Luna County), 2; Folsom, 1; Fort Wingate 
(McKinley County), 1; Gallup, 1; Garfield (Dona Ana County), 1; Gila 
(Grant County), 1; Gila National Forest (east fork Gila River), 1; Glen- 
wood (Catron County), 1; Grant (Valencia County), 3; Guadalupe 
Mountains, 1; Hachita, 3; HighroUs (Otero County), 4;" Hondo Canyon 
(Taos County), 1; Hondo River (White Mountains, Lincoln County), 1; 
Jicarilla Mountains, 3; Lincoln, 2; Lima (Catron County), 1; Magdalena 
Moimtains, 2; Manzano Mountains, 3; Mescalero, 2;" Mimbres Mountains 
(head of Rio Mimbres), 1; Mosquero (Harding County), 2;" Pecos (San 
Miguel County), 1; Red River (8,200 feet altitude, Taos County), 1; Red- 
rock (Grant County), 1; Riley (Socorro County), 2; Rinconada (Rio 
Arriba County), 2; Rio Puerco (Valencia County), 1; Ruidoso (Lincoln 
County), 1; San Luis Mountains, 0; San Pedro (Santa Fe County), 3; 
Santa Rosa, 4; San Mateo Mountains (Socorro County), 2; San Mateo 
Mountains (Valencia County), 1; Sierra Grande, 1; Sweetwater (15 miles 
southwest of Springer), 2; Tres Piedras (Taos County), 1; Tularosa, 3; 
Zuni Mountains (Valencia County), 2. 

Sonera: Bacerac (15 miles east), 1; Camoa, 1; Cerro Blanco, 3;^' Guadalupe 
Canyon (Monument 73, Mexican boundary line), 2; Hermosillo, 3; Mag- 
dalena, 1; Nogales (and 32 miles south), 8; Ortiz, 1; Pilares, 1; Provi- 
dentia Mines, 4;" San Jose Mountain (8 miles south of Monument 93, 
Mexican boundary line), 3; Santa Cruz, 1. 

Texas: Castle Mountains (Cx-ockett County), 1; Comstock (and 40 miles north- 
west), 2; Davis Mountains, 11; Devils River, 6; El Paso, 1; Fort Davis, 
2; Guadalupe Mountains, 2; Langtry, 1; Painted Cave (near mouth of 
Pecos River), 4; Pecos High Bridge, 1. 
Utah: Beaverdam Mountains, 1; Pine Valley (Washington County), 2; Santa 
Clara, 2. 

CITELLUS VARIEGATUS TULAROSAE Benson 

Malpais Rock Squibbel 

Citellus grammurus tularosae Benson, Calif. Univ. Pubs., Zool. Ser. 38: 336, 

Apr. 14, 1932. 
Otospennophilus grammurus tularofiae Bradt, Jour. Mammal. 13 : 324, 1932. 

Type. — Collected at French's Ranch, 5,400 feet altitude, 12 miles 
northwest of Carrizozo, Lincoln County, N. Mex., October 28, 1931, 

" Univ. Michigan Mus. Zool. 
** Cleveland ifus. Nat. Hist. 

^''D. R. Dickey collection (California Inst. Technology). 
«• New Mexico State College. 
*'' F'ield C^olumbian Mus. 
154970—38 10 



146 ' NORTH AMERICAN FAUNA [No. 56 

by Seth B. Benson; male adult, skin and skull, no. 50935, Mus. Vert. 
Zool. (orig.no. 1603). 

Range. — "Lava beds of the Tularosa Basin in Lincoln and Otero 
Counties, New Mexico" (Benson) (fig. 13). Zonal range: Lower 
Sonoran. 

External characters. — ^Very similar in color to typical G. v. vaHe- 
gatus., but bead never black and hinder back more tawny ; similar in 
size to G. V. grammurus but coloration distinctly darker (more black- 
ish), due largely to the darker bases of the hairs on both dorsal and 
ventral surfaces; hinder back darker tawny; hind feet slightly 
darker. 

Granidl characters. — Skull similar to that of grammurus (only one 
adult skull examined; extent of variation not known). 

Golor. — ^Winter pelage (October) : Head grizzled with fuscous or 
black and light buff ; eye ring white ; ears blackish externally, edged 
with buff, cinnamon buff on inner surface ; hairs on fore back fuscous 
black basally, tipped with white; hairs on hinder back dark fuscous 
basally, tipped with sayal brown and light buff; front feet pinkish 
buff, hind feet light pinkish cinnamon, all more or less grizzled with 
blackish; tail mixed black and grayish white; under parts grayish 
white or pinkish buff, the bases of the hairs dark fuscous. 

Measurements. — Adult male (type) : Total length, 488; tail vertebrae, 206; 
hind foot, 60; ear from notch (dry), 18. SuMdult female: 437; 172; 53; 17. 
Skull: Adult male (type) and subadult female: Greatest length, 63, 57.5; pala- 
tilar length, 30, 27; zygomatic breadth, 38.6, 34.7; cranial breadth, 25.8, 25.1; 
interorbital breadth, 15.5, 14.7; postorbital constriction, 18.3, 17.8; length of 
nasals, 23, 20.9; maxillary tooth row, 12.1, 11.8. 

Remarks. — The Malpais rock squirrel, although occupying a very 
limited area in south-central New Mexico, and entirely surrounded by 
another wide-ranging race — grammurus — is apparently a well- 
marked form. It appears to be confined exclusively to the beds of 
dark-colored lava rock where this and other dark forms of rodents 
have developed. 

Specimens examined. — Total number, 4, as follows : 

New Mexico : French's Ranch, 12 miles northwest of Carrizozo, 3 ; ^ Malpais 
Lava Beds (near Carrizozo), 1.** 

CITELLUS VARIEGATUS UTAH Merbiam 

Utah Rock Squirrel 

Citellus grammurus utah Merriam, Biol. Soe. Wash. Proc. 16 : 77, May 29, 1903. 
Citellus variegatus Utah Elliot, Field Columb. Mus. Pub. Zool. Ser. 6: 115, 1905. 
OtospermopJiilus grammurus utah Miller, U. S. Natl. Mus. Bull. 128: 181, 1924. 

Type. — Collected at foot of Wasatch Mountains, near Ogden, Utah, 
October 10, 1888, by Vernon Bailey; female adult, skin and skull, 
no. 186468, U. S. Natl. Mus. (Merriam collection, no. ) (orig. no. 
291). 

Range. — Central Utah, from the Wasatch Range south to the 
Beaver Mountains; also the Kaibab Plateau, Ariz, (limits of range 
imperfectly known) (fig. 13). Zonal range: Transition and Upper 
Sonoran. 



«Mus. Vert. ZooL 



1938] REVISION OF THE GROUND SQUIRRELS 147 

External characters. — Similar to C. v. grammurus^ but head and 
posterior back darker (more tawny), especially in unworn winter 
pelage. 

Cranial characters. — Skull similar to that of grammuruSs but aver- 
aging smaller. 

Color. — Winter pelage (October) : Head mixed pinkish buff and 
fuscous ; a broad buffy white eye ring ; shoulders and fore back gray- 
ish white, the bases of the hairs fuscous; hinder back snuff brown or 
mikado brown, sj)aringl3^ tipped with light buff ; lower sides grayish 
white; feet pinkish buff or grayish buff; tail mixed pale buff and 
fuscous black ; under parts buffy white or pale pinkish buff'. 

Molt. — An adult female (nursing) taken at Nephi, Utah, July 5, 
is in worn winter pelage and shows new pelage coming in on the 
head and nape. 

Measurements. — Average of 7 adult males from Utah (Ogden, Salt Lake City, 
Provo) : Total length, 467 (454-495) ; tail vertebrae, IDS (185-210) ; hind foot, 
G0.5 (59-63) ; ear from notch (dry), 19.5 (18.5-21). Average of 5 adult fe- 
males from Utah (Ogden, Provo, Salt Lake City, Marysvale) : Total length, 438 
(425-460); tail vertebrae, 189 (180-199): hind foot, 58.8 (56-61); ear from 
notch (dry), 18.7 (18-19). Skull: Average of 4 adult males from Utah (Ogden, 
Provo, Salt Lake City) : Greate.st length, 60.3 (57.5-63) ; palatilar length, 29.2 
(28-30.5) ; zygomatic breadth, 36.9 (35.5-38) ; cranial breadth, 25.3 (24.8-2-5.8) ; 
interorbital breadth, 14.7 (14.2-15.2) ; postorbital constriction, 17.5 (17.1-18.3) ; 
length of nasals, 21.1 (19.8-22.4); maxillary tooth row, 11.5 (11.4-12). Aver- 
age of 6 adult females from same localities: Gi'eatest length, 57.9 (5(>-59.5) ; 
palatilar length, 27.7 (27-28.5) ; zygomatic breadth, 35.6 (34.6-36.8) ; cranial 
breadth, 24.1 (23.5-24.6) ; interorbital breadth, 13.5 (13.2-14.3) ; postorbital 
constriction, 16.9 (16-17.5) ; length of nasals, 20.6 (18.9-21.9) ; maxillary tooth 
row, 11.3 (10.7-11.6). 

Remarks. — The Utah rock squirrel appears to be a recognizable 
race, but it is difficult to define the limits of its range. Upon com- 
parison of typical specimens in unworn v.inter pelage with a similar 
series of graramurus from southeastern Colorado — the type region — 
marked differences in color are noticeable. However, throughout the 
wide range of grammurus in New Mexico and Arizona many indi- 
vidual specimens are found that agree very closely in color with 
specimens of utah. But nowhere in northern Utah do we find speci- 
mens to match the pale grayish or cinnamon buff type occurring in 
Colorado, New Mexico, and southeastern Arizona. 

Two specimens from the Kaibab Plateau, Ariz., appear to be refer- 
able to Utah., but whether this race has a continuous range from the 
Beaver Mountains south to the Kaibab is not known; grammurus 
occurs in practically typical form in extreme southwestern Utah and 
southern Nevada. 

Specimens examined. — Total number, 34, as follows: 

Arizona: Big Spring (Kaibab Plateau), 1; Kaibab Forest, l.'^ 

Utah: Beaver, 1; Cedar Fort (Utah County), 1; Florence Canyon, 35 miles 

north of Green River (city), 6;°*" Logan, 3:"^^ Marysvale, 2; Murray 1; 

Nephi, 1; Ogden, 8; Parowan, 1;^^ Provo, 5; Provo Canyon, 1;" Salt Lake 

City, 2. 



«»Mus. Vert. Zool. 

^ Carnegie Mus. 

WTItah State. Agr. College. 

"^ Cleveland Mus. Nat. Hist. 



148 NORTH AMERICAN FAUNA [No. 56 

CITBLLUS BEBCHETI (Richardson) 
[Synonymy under subspecies] 

Speci-jh characters. — Size small to medium ; hind foot, 50-63.5 mm ; 
tail, 137-198; skull length, 51.6-62.4. Skull essentially similar to' 
that of O. variegatus grammurus except in size. 

Color. — Head varying from avellaneous or pinkish cinnamon to 
wood brown or sayal brown; upper parts snuff brown, wood brown, 
or sayal brown, flecked with buffy white or cinnamon buff; sides of 
neck and shoulders white or whitish, this color extending backward 
as two divergent stripes to about the middle of the back, leaving a 
dark triangular area between ; under parts buff, of varying intensity. 

CITELLUS BEECHETI BEECHEYI (Richakdson) 

CAUFOENIA GROtrND SQtriEBEIi 

(PI. 8) 

Arctomys (Spermophilus) heecheyi Richardson, Fauna Boreali- American a 1: 

170, 1829. 
Spermophilus deecheyi F. Cuvier, Sup. a I'hist. natur. Buffon 1 : 331, 1831. 
ISpermophilus prammurus] var. beecheyi Allen, Boston Soc. Nat. Hist. Proc. 

16: 293, 1874. 
Citellus variegatus beecheyi Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 114, 

1905. 
Oto spermophilus beecheyi Mearns, U. S. Natl. Mus. Bull. 56 : 324, 1907. 
Citellus grammurus beecheyi Miller, U. S. Natl. Mus. Bull. 79 : 298, 1912. 
Citellus beecheyi beecheyi Grinnell, Calif. Acad. Sci. Proc. (4) 3: 346, 1913. 
Otospermophilus grammurus beecheyi Miller, U. S. Natl. Mus. Bull. 128: 180, 

1924. 

Type. — No. 222a, British Museum, skin with skull inside ; locality 
not stated; habitat given as "neighborhood of San Francisco and 
Monterey, in California." 

Range. — ^Western California, from San Francisco Bay south to 
northern San Diego County; eastward through the coast ranges and 
the San Gabriel Mountains (fig. 14). Zonal range: Upper Sonoran 
and Transition. 

External characters. — Similar to C. variegatus grammurus but 
darker; white area of the shoulders divided by a dark triangular 
patch reaching to the crown ; ears darker on outer surface. Sunilar 
to C. h. dougla^ii, but slightly darker; white shoulder patches less 
extensive,, and foreback without a black patch between the white 
stripes. In comparison with the other races of heecheyi, this form 
is darker (more brownish) on the head and back, and more buffy 
on the under parts. 

Cranial characters. — Skull similar to that of C. v. grammurus but 
smaller and relatively narrower in the postorbital region; nasals 
narrower posteriorly. 

Color. — Fresh fall pelage (San Mateo County, Calif., December) : 
Top of head pinkish cinnamon, shaded with fuscous ; eye ring buffy 
white; ears fuscous black externally and on the upper margin, pale 
cinnamon buff on inner surface and posterior outer margin ; hairs of 
upper parts fuscous black at base, tipped with pinkish cinnamon, the 
general tone near snuff brown; sides of neck _ and shoulders dull 
white, this color extending backward as two divergent stripes that 
fade out about the middle of the back; sides of body more or less 



1938] 



REVISION OF THE GROUND SQUIRRELS 



149 



extensively flecked 
with dull white ; feet 
pale pinkish buff ; 
under parts pinkish 
buff ; tail mixed black 
and pinkish buff. 

Variation. — The 
pelage in simimer is 
slightly paler, due to 
wear and fading. 

Molt. — The annual 
molt occurs usually 
in July, but may be 
deferred imtil Sep- 
tember. An adult 
male from Marys- 
ville Buttes, taken 
July 15, is in much 
worn pelage and 
shows new pelage 
starting in a small 
area on the fore back. 
An adult female 
taken on the same 
day at the same place 
is in old worn pelage 
and shows no indica- 
tion of molting. A 
subadult male from 
Salinas, September 
4, shows new pelage 
on the head and the 
posterior half of the 
body. 

Measuremen ts. — Aver- 
age of 10 adult males 
from type region (Berk- 
eley, Walnut Creek, 
Stanford University, 
Boulder Creek, Monte- 
rey, Mansfield) : Total 
length, 434 (410-460) ; 
tail vertebrae, 177 (156- 
190) ; hind foot, HO (57- 
61 ) ; ear from notch 
(dry), 19.9 (18-21). 
Average of 10 adult fe- 
males from same sec- 
tion : Total length, 401 
(370-442) ; tail verte- 
brae, 158 (137-180) ; 
hind foot, 56 (53-59) ; 
ear from notch (dry), 
20.7 (19-22). Skull: 

Average of 20 adult males from Contra Costa County: Greatest length, 59.4 
(57-62.4) ; palatilar length, 28.8 (27-30.5) ; zygomatic breadth, 38.3 (36.3-40.5) ; 
cranial breadth, 24.5 (23.4-25.9) ; interorbital breadth, 14.7 (13.2-15.8) ; postorbi- 
tal constriction, 15.7 (14.8-16.9) ; length of nasals, 22.1 (20-24) ; maxillary tooth 
row. 12 (11.2-12.9). Average of 20 adult females from same locality: Greatest 




Figure 14. — Distribution of the subspecies of Citellus 
beecheyi: 1, C. b. doiiglasii; 2, C. b. sierrae; 3. O. h. ftsheri; 
4,0. b. beecheyi; 5, C. b. parvulus; 6, C. b. nesioticus ; 
7,(7. b. nudipes; 8, C. b. rupinarum. 



150 NORTH AMERICAN FAUNA [No. 56 

length, 57.1 (53.9-60.4) ; palatilar length, 27.5 (26^30) ; zygomatic breadth, 36 
(33.6-38.6) ; cranial breadth, 23.6 (22.7-25.2) ; interorbital breadth, 13.8 (12.9- 
15.4) ; postorbital constriction, 15.6 (13.7-16.7) ; length of nasals, 21 (19.7-22.4) ; 
maxillary tooth row, 11.9 (10.6-12.7). 

RemarJcs. — Any attempt to divide C. heecheyi into subspecies is 
certain to be unsatisfactory ; this is because of the large amount of 
individual variation that is found in all races and also because of 
the diversified nature of the country in which the animals live. The 
present race is the darkest of all the forms and is typical only in the 
coastal region from San Francisco Bay southward to Ventura 
County ; from there southward the animals become paler and smaller, 
grading into C. h. -fisheri in the Tehachapi Mountains, into G. h, 
parvulus in the San Bernardino Mountains, and into C. h. nudipes 
in the coastal region of San Diego County. In many localities, the 
variation in the series is so great that while some of the specimens 
are typical of beecheyi, one or more may closely resemble one of the 
other subspecies. 

Specimens examined. — Total number, 197, as follows: 

California: Alhambra, 1; Aptos (5 miles south, Santa Cruz County), 2; Arroyo 
Seco (10 miles south of Paraiso Springs, Monterey County), 2; Arroyo Seco 
Canyon (near Pasadena. Los Angeles County), 3;" Bear Basin (head of 
Carmel River, Monterey County), 1; Berkeley, 2; Bitterwater (San Benito 
County), 3; Boulder Creek (Santa Cruz County), 3; Corral Hollow (8 
miles southwest of Tracy), 1;^ Contra Costa County, 50 (skulls) \^^ Cor- 
ralitos (Santa Cruz County), 11; ^ Del Norte (7 miles southeast, Monterey 
County), 6; Fremont Peak (Gabilan Range, Monterey County), 1; Gaviota 
Pass (Santa Barbara County), 2; Half Moon Bay, 1; Hay ward, 1; Idria 
Mines (San Benito County), 4; Jamesburg (Monterey County), 1; Jolon 
(Monterey County), 1; Laguna Ranch (Gabilan Range, San Benito County), 
1; Las Virgines Creek (Los Angeles County), 1: Los Gatos, 1; Lytle Creek 
(San Bernardino County), 1; Mansfield (Monterey County), 4; Monterey, 
6; Pacific Grove (Monterey County), 1; Paraiso Springs (Monterey County). 
4; Paso Robles, 1; Pescadero, 1; Pine Valley (head of Carmel River, Mon- 
terey County), 2; Posts (Monterey County), 1; Pozo (San Luis Obispo 
County), 3; Priest Valley (Monterey County), 1; Redwood City, 1; Salinas, 
1; San Francisco, 6; San Gabriel, 1; San Gabriel Mountains (Heninger 
Flats), 8; San Luis Obispo, 1; San Pedro (Point Firmin). 10; San Rafael 
Mountains (Santa Barbara County), 1; San Simeon (San Luis Obispo 
County), 2; Santa Barbara, 3; Santa Clara, 1; Santa Cruz, 2; San Mateo, 
1; Santa Inez Mission (Santa Barbara Comity), 2; Santa Monica, 1; Sea- 
side (Monterey Coimty), 7; Sisquoc (Santa Barbara County), 3; Soledad, 
1; Stanford University, 1; Strawberry Peak (San Gabriel Mountains), 1; 
Sur (Monterey County), 1; Tassajara (Contra Costa County), 1; Temescal 
(Riverside County), 2; Ventura River, 1; Walnut Creek (Contra Costa 
Comity), 5; "Wilson Peak (Los Angeles County), 9. 

CITELLUS BEECHETI DOUGLASII Richardson 

Douglas's Ground Squirrel 

(Pis. 8; 26, B; 31, B) 

Arctomys? (Spermophihts?) douglasii Richardson, Fauna Boreali- Americana, 

1 : 172, 1829. 
Spermophilus douglasii F. Cuvier, Sup. a I'hist. natur. Buffon 1 : 333, 1831. 
[Spermoplnlus grammurus'] var. douglassi Allen, Boston Soc. Nat. Hist. Proc. 16 : 

293, 1874. 
Citellus V. douglasi Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 183, 1903. 
Citellus 'beecTieyi douglasi Grinnell, Calif. Acad. Sci. Proc. (4) 3 : 345, 1913. 



53 Mus. Vert. Zool. 

^ Univ. Michigan Mus. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS 151 

Otospennophilus grammiints dotifflasii Miller, U. S. Natl. Mns. Bull. 128: 180, 
1924. 

Type. — None designated ; description based on a hunter's skin from 
the "banks of the Cokimbia" [River], sent to E-ichardson by David 
Douglas. 

Range. — Western Oregon and northern California, from tlie Colum- 
bia River Valley south nearly to San Francisco Bay, Calif.; east to 
the Deschutes River Valley, Oreg. ; Lake City, Calif., and a line 
reaching from the latter point to Eagle Lake. Lyonsville, Magalia, 
and Nelson ; from there southward occurring only west of the Sacra- 
mento River (fig. 14). Zonal range: Mainly Upper Sonoran and 
Transition; into Lower Sonoran in the Sacramento Valley and into 
Canadian on the Siskivou Mountains (6,000 feet) and the Scott 
Mountains (6.800 feet)." 

Exteimal characters. — Similar in general tone of upper parts to 
C. h. heecheyi^ but averaging paler, especially on the head; a large 
triangular black patch on the foreback between the white shoulder 
patches ; ears paler ; under parts slightly paler ; tail averaging longer, 
and paler underneath. Compared with C. h. fisheri: Back darker, 
with a black wedge between the shoulders; tail averaging longer, and 
deeper buff beneath. 

Cranial characters. — Skulls of adult males average larger than those 
of heecheyi while skulls of females average smaller. 

Color. — Fresh pelage (October) : Nose and face smoke gray, 
washed with pinkish cinnamon; crown mikado brown or cinnamon; 
ears fuscous on outer surface, pale cinnamon buff on inner surface; 
eye ring creamy white ; shoulder patches pale smoke gray, enclosing a 
wedge-shaped patch of fuscous black; general tone of hinder back 
near sayal brown, mottled with pale smoke gray or pale pinkish buff; 
front feet pinkish buff; hind feet varying from cartridge buff to cin- 
namon buff; tail above, mixed black and pale pinkish buff, the hairs 
edged with grayish white ; tail beneath, cinnamon buff or light ochra- 
ceous buff, more or less obscured with grayish white; under parts 
cartridge buff, pinkish buff, or grayish white. 

Variation. — Occasional specimens lack the black patch on the back ; 
in a series of 20 specimens from The Dalles, Oreg., one in fresh pelage 
lacks the black patch entirely and four in worn pelage have the black 
nearly obliterated. 

Molt. — The annual molt takes place usually in June or July, but 
may sometimes be delayed till August or early September, Certain 
individuals in spring and early summer become greatly worn before 
molting, so that the blackish patch on the fore back becomes faded or 
nearly obliterated. 

Specimens taken at The Dalles, Oreg., June 10, show new pelage 
coming in on the head and fore back; female specimens from Still- 
water, Calif., July 1, and Drew, Oreg. July 28, are in similar condi- 
tion of pelage; nursing females from Forest (jrove, Oreg., July 16, 
and Tower House, Calif., August 4, are in badly worn pelage and had 
not started to molt ; another nursing female, from Chico, Calif., Sep- 
tember 19, had just acquired a fresh pelage over the anterior half of 
the back, the hinder back being in worn and faded pelage. 

Measurements. — Averago of 10 adult males from Oregon: Total length, 476 
(450-500) ; tail vertebrae, 207 (190-223) ; hind foot, 61 (56-6Li) ; ear from notch 



1 52 NORTH AMERICAN FAUNA [No. 56 

(dry), 19.5 (17.5-22). Average of 10 adult females from Oregon: Total length, 
450 (440-460) ; tail vertebrae, 193 (182-200) ; hind foot, 58.6 (57-60) ; ear from 
notch (dry), 18.4 (17-20). Skull: Average of 8 adult males from Oregon: Great- 
est length, 61.5 (59.2-63.2) ; palatilar length, 30.1 (29.2-31) ; zygomatic breadth, 
38.1 (36.3-39.9) ; cranial breadth, 24.5 (24-25) ; interorbital breadth, 14.2 (13.3- 
15.7) ; postorbital constriction, 15.1 (14.5-15.8) ; length of nasals, 22 (20.5-23.5) ; 
maxillary tooth row, 11.5 (11.1-12). Average of 10 adult females from The 
Dalles, Oreg. : Greatest length, 56.1 (54.6-57.8) ; palatilar length, 26.9 (26-27.8) ; 
zygomatic breadth, 34.1 (33.2-35.3) ; cranial breadth, 23.1 (22-24) ; interorbital 
breadth, 12.8 (11.5-13.4) ; postorbital constriction, 15.8 (14.9-16.9) ; length of 
nasals, 19.3 (18.5-20.6) ; maxillary tooth row, 10.8 (10.1-11.2). 

Remarks. — Douglas's ground squirrel is closely related to 
beecheyi, differing chiefly in having a large black patch on the fore- 
back between the whitish side stripes; the range of douglasii is 
separated from that of fisheri by the Sacramento River for a con- 
siderable distance in central California, but in the vicinity of Chico, 
douglasii crosses to the east side of the river and meets the range of 
■fisheri in Butte County. Typical specimens of douglasii have been 
collected at points nine miles east of Chico and eight miles east of 
Nelson. At Oroville and Yankee Hill typical fisheri occurs, while at 
Cherokee and Pentz typical specimens of each and some with inter- 
mediate characters have been taken. This condition suggests hybrid- 
ization rather than the usual type of intergradation, but in considera- 
tion of the close resemblance between the two forms in color and 
with no important difference between them in skull characters, it 
seems best to treat them as subspecies. 

The present species is reported to have crossed the Columbia River 
and established itself near White Sahnon, Wash., within very re- 
cent times. In July 1917, W. N. Suksdorft stated that it had come 
in within the past 2 or 3 years and had already spread for 2 or 3 
miles up the river valley. 

Specimens examined. — Total number, 338, as follows: 

California: Adin (Modoc County), 7; Bald Mountain (8 miles south, Shasta 
County), 2; Balls Ferry (Shasta County), 1;" Bartlett Mountain (Lake 
County), 2; Bear Creek Valley (Shasta County), 1; Beswick (Siskiyou 
County), 6; Bieber (Lassen County), 1; Branscomb (Mendocino County), 
1;°* Burney (Shasta County), 4; Cahto (Mendocino County), 1; Calpella 
(Mendocino Comity), 1; Cassell (Shasta County), 5; Cherokee (Butte 
County), 2;'° Chico, 17; Cloverdale, 3; Dana (Shasta County), 3; Davis, 
1; Dry Creek (Butte County), 4;" Eagle Lake (Lassen County), 2; Eel 
River (Humboldt County), 6; Elmira (Solano County), 1; Eureka, 3;" 
Fairfield, 6; Fall River Mills, 1; Fort Crook (Shasta County), 6; Glen 
Ellen (Sonoma County), 13; Goose Lake, 3; Guenoc (Lake County), 1; 
Hayden Hill (Lassen County), 4; Healdsburg, 1; Hoopa Valley (Huml)oldt 
County), 7; Hornbrook, 3; Mad River (Carson's Camp, Humboldt Bay), 2; 
Lake Cit.v (Modoc County), 1; Lakeport, 1; Lower Lake (Lake County), 
3; Lyonsville (Tehama County), 2; Magalia (Butte County), 1; Merrill- 
ville (Lassen County), 1; Middletown (Lake County), 1; Mill Creek (east 
of Lyonsville, Tehama County), 1; Montague, 1; Mount George (Napa 
County), 1; Mount St. Helena (Sonoma County), 2; Mount Veeder (10 
miles N. W. of Napa), 2; Nelson (Butte County), 2; North Yolla Bolly 
Mountain (12 miles north. Trinity County), 1;°° Paynes Creek (Tehama 
County), 1; Pentz (Butte County), 4;°' Petaluma, 3; Pittville (Shasta 
County), 1; Red Bluff, 11; Redding, 5; Redding-Bieber road (12 miles west 
of Burney), 3; Round Mountain (Shasta County), 1; Saint John (Glenn 
County), 3; Salt Creek (6 miles northwest of Baird, Shasta County), 1; 
Salmon Mountains (near Etna Mills, Siskiyou County), 5; Shasta Valley 



^ Univ. Michigan Mus. Zool. 
E« Mus. Vert. Zool. 
"Field Mus. Nat. Hist 



1938] REVISION OF THE GROUND SQUIRRELS 153 

(Siskiyou County), 1; Sherwood (Mendocino County), 3; Siskiyou Moun- 
tains (White Mountain), 7; Sisson (Siskiyou County), 8; Sites (Colusa 
County), 1; Smith River (Del Norte County), 2; South Tolla Bolly Moun- 
tain (Trinity County), 1; Stillwater (Shasta County), 2; Tehama, 1; 
Tower House (near Bally Mountain, Shasta County), 1; Tule Lake (east 
side), 1; Ukiah, 5. 

Oregon: Ashland, 3; Beaverton (Washington County), 1; Blaine (Tillamook 
County), 3;°° Dog Lake Ranger Station (30 miles southwest of Lakeview), 
1; Douglas County (22 miles east of Drew), 1; Elk Head (Douglas 
County), 1; Eugene, 3; Farren Ranger Station (13 miles southwest of 
Galice), 1; Forest Grove, 11; Fort Klamath, 1;'° Gold Beach, 4;" Grants 
Pass, 10; Hood River, 4; Klamath Lake, 2; Mapleton (Lane County), 1; 
Maupin (Wasco County), 8; McCoy (Polk County), 4; McKenzie Bridge 
(10 miles east. Lane County), 5; Miller (Sherman County), 3; Mount 
Hood (north slope, 2,800 feet altitude), 1; Naylox (=Algoma, Klamath 
Lake), 2; Oregon City, 1; Philomath, 3; Portland, 2; Prospect (Jackson 
County), 6; Reston (Douglas County), 1; Rogue River Valley (near 
Grants Pass), 4; Roseburg, 5; Salem, 3;" Scottsburg (Douglas Coimty), 1; 
Siskiyou (Jackson County), 1; The Dalles, 20; Tillamook, 1 ;"* Wapinitia 
(Wasco County), 1; Warm Springs (Jefferson County), 2; Warm Springs 
River (Wasco County), 2. 

Washington: White Salmon, 3. 

CITELLUS BEECHEYI SIERRAE, sxjbsp. nov. 
Sierra Ground Squtbrei- 

Type. — Collected at Emerald Bay. Lake Talioe, Calif., May 23, 
1897, by J. Alden Loring; female adult, skin and skull, no. 88421, 
IT. S. Natl. Mus. (Biological Survey collection) (orig. no. 4166.) 

Range. — Higher parts of the northern Sierra Nevada, from Plumas 
County south to Mariposa County (upper Merced River) (fig. 14). 
Zonal range: Transition and Canadian. 

External characters. — Similar in size and color of upper parts 
to C. h. 'beecheyi; sides of head more grayish (less huffy) ; feet more 
whitish (less huffy) ; under parts averaging paler (more whitish) ; 
under side of tail more grayish (less huffy). Compared with C. h. 
fisheri: Head and upper parts distinctly darker; feet more whitish 
(less huffy) ; tail darker and less huffy beneath. 

Cram at characters. — Skull similar to that of heecheyi., but aver- 
aging slightly smaller, except in the postorbital breadth, which ig 
greater. 

Color. — Winter pelage (type. May 23) : Head sayal brown, washed 
with grayish white; sides of face fuscous, the hairs tipped with 
grayish white; ears fuscous black, shaded on posterior margin with 
grayish buff; general tone of upper parts pale sayal brown, flecked 
witii huffy white; sides of neck and shoulders with a heavy wash of 
grayish white, and sides of body less heavily washed with the same ; 
hind feet grayish white, front feet pale buffy white; tail above, 
fuscous black, mixed with grayish white; tail beneath, mixed buffy 
w^hite and fuscous black; under parts pinkish buff. 

Variation. — In some specimens, the upper parts are snuff brown, 
flecked with cinnamon buff and buffy white; the head is sometimes 
pure sayal brown, without grayish wash. 

Measurements. — Average of 3 adult males from vicinity of Lake Tahoe 
(Emerald Bay, Tallac. and Emigrant Gap) : Total length, 452 (44(M70) ; tail 
vertebrae, 17S (170-100) : hind foot, 57.7 (54-63); ear from notch (dry), 20 



•' Ilnlv. Michigan Mus. Zool. 
"T Field Mus. Nat. Rist. 



3^54 - NORTH AMERICAN FAUNA [No. 56 

(19-21.5). Average of 10 adult females from Emerald Bay, Dormer, and Little 
Yosemite: Total length, 422 (400-455) ; tail vertebrae, 172 (159-184) ; hind foot, 
56.2 (54-60) ; ear from notch (dry), 20.3 (18.5-2.3). Skull: Average of 5 adult 
males from Emerald Bay, Blue Canyon, and Emigrant Gap : Greatest length, 
58 (56.5-59.5) ; palatllar length, 27.7 (26.5-29) ; zygomatic breadth, 36.7 (34.9- 
37.8) ; cranial breadth, 23.5 (22.4^24.6) ; iuterorbital breadth, 14.1 (12.9^15.5) ; 
postorbital constriction, 16.1 (15.7-17.1) ; length of nasals, 20.9 (20.5-21.9) ; 
maxillary tooth row, 11.4 (11-11.8). Average of 11 adult females from Emerald 
Bay, Blue Canyon, and Donner: Greatest length, 56.6 (53.1-59.9); palatllar 
length, 27 (25-28) ; zygomatic breadth, 34.4 (33.1-36.9) ; cranial breadth, 23.4 

(22.7-24.9) ; interorbital breadth, 14 (13.5-15) ; postorbital constriction, 16.2 

(15.2-17) ; length of nasals, 20.8 (19.5-21.8) ; maxillary tooth row, 11.1 

(10.5-11.7). 

Remarks. — The Sierra ground squirrel bears a close resemblance 
to typical heecheyi., but differs in certain minor characters as pointed 
out above; it might be included with heecheyi except for the fact 
that their ranges are not contiguous, being separated by the range of 
-fisheri^ the pale form occupying the San Joaquin and Sacramento 
Valleys. Intergradation with fisheri occurs in the southern Sierra 
Nevada and along the lower slopes on the western side of the range. 

Specimens examiiied. — Total number 39, as follows: 

California: Big Trees (Calaveras County), 1; Blue Canyon (Placer County), 
14; Downieville, 1; Emerald Bay (Lake Tahoe), 5; Emigrant Gap (Placer 
County), 1; Little Yosemite (Mariposa County), 1; Markleeville (Alpine 
County), 4; Merced River (near head), 3; Quincy, 1; Summit (=Donner, 
Placer County), 5; Tallac (Eldorado County), 2; Wawona (south fork 
Merced River, Mariposa County), 1. 

CITELLUS BEECHEYI FISHERI Meeeiam 
Fisher's Ground Sqxjireel 

Spermophilus heecheyi fisheri Merriam, Biol. Soe. Wash. Proc. 8: 133, Dec. 28, 

1893. 
[Spermophilus fframmurus] fisheri Elliot, Field Columb. Mus. Pub., Zool. Ser. 

2: 88, 1901. 
Citellus variegatus fisheri Elliot, Field Columb. Mus. Pub., Zool. Ser. 3: 211, 

1903. 
Citellus becchciji fisheri Grinuell, Calif. Acad. Sci. Proc. (4) 3: 346, 1913. 
Otospennophilus grammurus fisheri Miller, U. S. Natl. Mus. Bull. 128: 181, 

1924. 

Type. — Collected on South Fork of Kern River, 3 miles above 
Onyx, Kern County, Calif., July 6, 1891, by A. K. Fisher; male sub- 
adult; skin and skull, no.|fff|,'U. S. Natl! Mus. (Biological Survey 
collection) (orig. no. 741). 

Range. — Greater part of central California, including the San 
Joaquin and Sacramento Valleys and the southern Sierra Nevada; 
north on the eastern side of the Sacramento River to southern Butte 
County, then northeastward to Susanville; east to the western side 
of Pyramid Lake, Nev., and to Walker Pass, in the southern Sierra 
Nevada, Calif. ; south to the Tehachapi Mountains ; west to Cuyama 
Valley, the Carriso Plain, and the western border of the San Joaquin 
Valley (fig. 14). Zonal range: Upper Sonoran and Transition. 

External characters. — Similar in size to C . h. 'heecheyi, but hind 
feet shorter ; coloration paler, both above and below ; light markings 
on shoulders more prominent and clearer white. 

Cranial characters. — Skull similar to that of heecheyi but averag- 
ing smaller, especially in the females; zygomata less widely 
expanded. 



1938] REVISION OF THE GROUND SQUIRRELS 155 

Color. — Smnmer pelage (Kern Valley) : Top of head and face 
light pinkish cinnamon; sides of face pale smoke gray; a large patch 
of clear creamy white on each shoulder, this color extending to the 
middle of the back in two narrow stripes separated by a dark area 
more or less triangular in shape; rest of upper parts about wood 
brown in general tone, flecked with patches of creamy white; feet 
pale buff or buffy white ; tail mixed fuscous black and pmkish buff ; 
under parts creamy white to pinkish buff'. Winter pelage (Modesto, 
February) : General tone of upper parts (excepting head) pale 
smoke gray, faintly washed with pale pinkish buff; under parts pale 
pinkish buff ; tail mixed fuscous black and pale pinkish buff. 

Molt. — The annual molt may occur at any time between May and 
August; an adult male from Modesto, taken May 8, shows new pelage 
coming in on the head, nape, and fore back; a male taken at JNIilford 
(Honey Lake), June 20, shows new pelage covering the posterior 
half of the body, and small areas on the head, shoulders, and fore 
back; a male from Biggs, Butte County, shows small areas of new 
pelage on the crown and in the middle of the back, behind the 
shoulders; a male from Carriso Plain, taken August 1, shows new 
pelage on the head and a large patch on the hinder back. 

Measurements. — Average of 7 males (adult and subadult) from Kern River 
Valley and Walker Basin: Total length, 442 (415H175) ; tail vertebrae, 183 (175- 
19S) ; hind foot, 57.6 (54-62) ; ear from notch (dry), 1S.4 (17-2C0. Average of 
4 adult females from Kern River Valley: Total length, 407 (390-427) ; tail verte- 
brae, 162 (155-170) ; hind foot, 52.7 (50-56) ; ear from notch (drv), 18.3 (17- 
20). Average of 11 adult males from Modesto: Total length, 457 (433-500) ; 
tail vertebrae, 107 (140-190) ; hind foot, 60.1 (55-63) ; ear from notch (dry), 
19.3 (17.5-21) ; average of 4 adult females from Modesto: 423; 168; 55.4; 17.7. 
Skull: Average of 4 adult males from Kern River Vallev and Walker Basin: 
Greatest length, 59.3 (57-60.9) ; palatilar length, 28.7 '(27.5-30) ; xvgomatic 
breadth, 36.9 (36.0-37.4) ; cranial breadth, 24.2 (23.8-24.7) ; interorbital" breadth, 
13.5 (11.5-14.3) ; postorl>ital constriction, 16 (15.2-17) ; length of nasals. 22.2 
(21.5-22.8) ; maxillary tooth row, 11.8 (11.7-12). Average of 3 adult females 
from Kern River Valley: Greatest length. 55.8 (55.6-50) ; ]ialatilar length. 26.5 
(26-27) ; zygomatic breadth, 34.2 (33.9-.34.6) ; cranial breadth, 23.1 (22.4-23.5) ; 
interorbital breadth, 13.7 (13.4-14) ; postorbital constriction. 15.3 (14.6-16) ; 
length of nasals, 20.1 (19.6-20.8) ; maxillary tooth row, 11.4 (11.1-11.7). Aver- 
age of 15 adult males from Modesto: Greatest length, 59.5 (55.5-62) ; palatilar 
length. 29.9 (27.5-31) ; zygomatic breadth. 37.5 (.•^4.2-.3S.9) ; cranial breadth, 
23.8 (22.2-24.9) ; interorbital breadth. 14.5 (13..3-16.5) ; postorbital constric- 
tion, 16 (15-16.9) ; length of nasals, 21.8 (20.2-22.S) : maxillary tooth row, 11.7 
(11.1-12.3). Average of 6 adult females from Modesto: Gre.-\test length. .56.3 
(55.3-.57.5) ; palatilar length, 27.1 (26-28) ; zygomatic lireadth. 35 (33.8-35.8) ; 
cranial breadth, 23.4 (22.7-24.8) ; interorbital breadth, 13.7 (12.6-14.7) ; post- 
orbital constriction, 15.5 (14.6-15.9) ; length of nasals, 20 (19.2-20.7) ; maxillary 
tooth row, 11.6 (10.9-12.) 

Remarks. — Fisher's ground squirrel is about the size of heecheyi., 
but averages decidedly paler in color; it is similar to O. h. parindiis in 
color, but is distinctly larger. Over its extensive range in botli valley 
and mountain country it is subject to considerable variation in color, 
and many individual specimens are scarcely different from some 
individuals of heecheyi. 

Intergradation with heecheyi occurs along the western side of the 
San Joaquin Valley and in the Tehachapi Mountains, with sierrae in 
tlie foothills of the Sierra Nevada and with douglasii in Butte 
County. 



156 NORTH AMERICAN FAUNA [No. 56 

Specimens examined. — ^Total number, 279, as follows : 

Caifornia: Alcalde (Fresno County), 3; Alila ( =Earlimart, Tulare County), 
8; Alta Peak (Kaweah River, Tulare County), 1; Aspen Meadow (Yosemite 
National Park), 4; Auburn (Placer County), 2; Bakersfield (Smiles north- 
east), 1," Biggs, 3; Bodflsh (Kern County), 1;" Camp Badger (Tulare 
County), 1; Cannell Meadow (Tulare County), 1;°* Carbondale (Amador 
County), 2; Carriso Plain, 5; Claribel (Stanislaus County), 1;°* Colusa (6 
miles east), 1; Coulterville, 1; Cuyama Valley (San Luis Obispo County), 2; 
Dos Palos, 1 ; Dry Creek (Butte County), 1 ; "^ Earlimart, 2 ; ^ Eshom Valley 
(Tulare County), 1; Feather River Station (Butte County), 2; '* Fort Tejon 
(Kern County), 13; Fresno 4; Fresno Flat (Madera County), 4; Grabner 
(Fresno County), 6;^° Greenville (Plumas County), 1; Horse Corral Mead- 
ows (Fresno County), 1; Jackass Meadow (Tulare County), 1 ; ** Jordan 
Hot Springs (Tulare County), 1 ; '^ Kern Lake (Tulare County), 1; Kern 
River (15 miles northeast of Bakersfield), 1; Kern River (Isabella and 12 
miles below Bodfish), 4; °* Kern River (South Fork, near Onyx), 12; Kern- 
ville, 2; La Grange (Stanislaus County), 1; Lemoore, 3; Long Valley (Las- 
sen County), 1; Los Banos (Merced County), 9; Maricopa, 4;^ Marysville, 
1; Marysville Buttes, 7; Milford (Lassen County), 2; Milo (Tulare County), 
2; Mineral King (East Fork Kaweah River, Tulare County), 1; Modesto, 
31 ; Mono Flats (Santa Barbara County), 2; Mountain House (6 miles south- 
west of Downieville ) , 2 ; Mount Finos, 7 ; Mount Whitney, 1 ; Nevada City, 
2; Orosi (Tulare County), 7; Oroville (Butte County), 1;^ Pacheco Pass 
(Santa Clara County), 2 ; Placerville (Eldorado County), 3 ; Plumas County, 
1; Porterville, 1; Prattville (Plumas County), 2; Raymond (Madera Coun- 
ty), 2; Redwood Mountain (General Grant National Park), 1 ; Ripon, 2; Rose 
Station (6 miles north of Old Fort Tejon), 2; Sacramento, 3; Salt Springs 
(Fresno River, 30 miles east of Raymond), 1; San Emigdio (Kern County), 
1; San Emigdio Canyon, 2; San Emigdio Creek, 2; ^ Sierra Valley (Plumas 
County), 2; Sequoia National Park, 2; Soquel Mill (head of North Fork of 
San Joaquin River), 2; Sunset Station (near Maricopa, Kern County), 1; 
Susanville. 1; Taylor Meadow (Tulare County), 5;^ Tehachapi, 2; Teha- 
chapi Peak, 3; Tejon Canyon, 3; Tejon Pass, 4; Three Rivers (Tulare 
County), 2; Tipton (Tulare County), 5;°* Tracy, 1; Trout Creek (Tulare 
County, altitude 6,000 feet), 3 ; '' Trout Meadows (Tulare County), 1 ; Volta 
(Merced County), 2; Walker Basin (Kern County), 1; Walker Pass (Kern 
County), 4; Weldon (Kern County), 3; Yankee Hill (Butte County), 1; 
Yosemite Valley, 3; Zaca Lake (Santa Barbara County), 1. 

Nevada: Carson City, 1; Genoa, 1; Glenbrook (Douglas County), 3; Pyramid 
Lake (west side), 4; Reno, 3; Verdi, 6; Virginia Mountains (Washoe 
County), 1. 

CITBLLUS BEECHEYI PARVULUS Howell 

Lessee Califoenla. Ground Squieeel 
(Pis. 26, A; 31, A) 

Citellus heecheyi parviilus Howell, Jour. Mammal. 12 : 160, May 14, 1931. 

Type. — Collected in Shepherd Canyon, Argus Mountains, Calif., 
April 30, 1891, by A. K. Fisher; female subadult, skin and skull, no. 
^^%^, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 
569 J. 

Range. — Desert ranges of southern California (except the Provi- 
dence Mountains) ; north to Owens Valley; south to the San Jacinto 
Mountains (fig. 14). Zonal range: Mainly Upper Sonoran and 
Transition, but extending into Lower Sonoran. 

Oranial characters. — Similar to O. h. -fislieri^ but smaller. 

Color. — Not appreciably different from that of -jisheri. 

=8 Mus. Vert. Zool. 

^ Cleveland Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 157 

Measurements. — Average of 10 adult males from Panamiut Mountains, Argus 
Mountains, and Owens Valley : Total length, 411.8 (383-435) ; tail vertebrae, 
162.8 (155-179) ; hind foot, 54.8 (50-58) ; ear from notch (dry), 19.8 (18-21). 
Average of 12 adult females from same section: Total length, 410 (885-455) ; 
tail vertebrae, 163 (145-180) ; hind foot, 52.9 (50-56) ; ear from notch (dry), 
19 (17-22). Skull: Average of 7 adult males from Panamint Mountains, Argus 
Mountains, Lone Pine, and Owens Lake: Greatest length, 56.3 (53.9-60.5) ; 
palatUar length, 26.8 (25-28) ; zygomatic breadth, 35.8 (34-36.4) ; cranial 
breadth, 23.3 (22.7-24.4) ; interorbital breadth, 12.8 (11.8-13.3) ; postorbital 
constriction, 14.9 (13.6-16.1) ; length of nasals, 20.9 (19.4-22.2) ; maxiUary tooth 
row, 11.1 (10.9-11.8). Average of 9 adult females from same region: Great- 
est length, 53.9 (52.2-54.8) ; palatilar length, 25.4 (25-26) ; zygomatic breadth, 
33.6 (32.6-34.7) ; cranial breadth, 23.2 (22.8-24.1) ; interorbital breadth, 13.3 
(12.4-14.1) ; postorbital constriction, 15.8 (14.8-16.4) ; length of nasals, 19.4 
(18.&-20.8) ; maxillary tooth row, 11.3 (10.8-11.7). 

Weight. — One old female from Olancha weighed 655 g. 

Remarks. — ^In the original description of this race, the present 
writer defined its range as extending southward to the San Pedro 
Martir Mountains, Baja California; since then, Huey (1931, p. 18) 
has described the form from northern Baja California as G. h. 
liudipes^ and as a result of further intensive study of a large series of 
specimens from the type region of nudipes and from extreme southern 
California, it seems proper to restrict the name pai^ulus to the 
small California race as far south as the San Jacinto Mountains, and 
to refer the series from San Diego County southward to nudipes. 

Huey objects to the recognition of parvulus on the ground that 
there is no appreciable difference between specimens from the type 
locality of fisheri (South Fork of Kern River) and those from the 
type locality of parvulus (Argus Mountains) ; comparison of the 
cranial measurements of seven specimens (four males, three females) 
of fisheri from the type region given on page 155 with the measure- 
ments of parvulus (above) shows, however, a decided difference in 
size of the skulls. It is true that the topotype series of -fisheri is 
slightly smaller in average cranial measurements than the series from 
the San Joaquin Valley, but the difference in size is much less than 
between topotypes of fisheri and of parvulus. 

The present race intergrades with fsheri in the Piute Mountains, 
with 0. h. beecheyi in the San Bernardino Mountains, and with 
nudipes in the San Jacinto Mountains. The series from the San 
Bernardino Mountains is so nearly intermediate between heecheyi 
and parvulus that it makes little difference which name is applied 
to it ; in fact, some specimens are practically typical of one race, some 
of the other. The skulls average smaller than those of heecheyi. 
The series from the San Jacinto Mountains is likewise intermediate 
between parvulus and nudipes, but a little nearer parmdus. The 
skulls average a little smaller than the San Bernardino series. 

Specimens examined. — Total number, 160, as follows : 

California: Argus Range (Inyo County), 3; Andreas Canyon (Riverside County), 
1;** Banning, 13; Cabazon (Riverside County), 11;°* Cameron (Kern 
County), 2; Coso (Inyo County), 6; El Ca.sco (Riverside County), 1; 
Hesperia (San Bernardino County), 2; Independence, 4;*" Independence 
Creek (6.500 feet altitude), 1; Jackass Spring, Panamint Mountains, 
11 ;~ "Little Lake (Inyo County), 2; Little Onion Valley (Inyo County), 
1;" Little Cottonwood Creek (Inyo County), 1;°" Lone Pine, 5; Mount 
William.son (N, E. base), Owens Valley, 3;" Old Camp Independence, 

"Mus. Vert. Zool. 

«' Cleveland Mus. Nat. Hist. 

" Two in Cleveland Mus. Nat. Hist. 



158 NORTH AMERICAN FAUNA [No. 56 

Owens Valley, 1;" Olancha (Inyo County), 1;*" Oro Grande, 8; Owens 
Lake, 6 ; Owens Valley, 2 ; Panamint Mountains, 5 ; Piute Mountains, 1 ; 
Palm Springs, 8; Reclie Canyon (San Bernardino County), 4; Riverside, 
1; San Bernardino, 7; San Bernardino Mountains, 15; San Jacinto 
Mountains, 32;'° Snow Creek (near Wliitewater, Riverside County), 1;^ 
Victorville, 1."" 

CITELLUS BEECHEYI NUDIPES HuEY 

Juarez Ground Squirrei. 

CiteUvs beecheyi nndlpes Huey, San Diego Soc. Nat. Hist. Trans. 7: 18, Oct. 6, 
1931. 

Type. — Collected at Hanson Laguna. Sierra Jnarez, Baja Cali- 
fornia, Mexico (latitude 31° 58' north, longitude 115° 53' west; alti- 
tude 5,200 feet), October 13, 1926, by Frank Stephens; female adult, 
skin and skull, no. 2015, San Diego Soc. Nat. Hist. 

Range. — Northern Baja California and extreme southwestern 
California, including most of the western half of San Diego County 
(fig. 14), Zonal range: Upper and Lower Sonoran and Transition. 

External characters. — Similar to C. h. heecheyi but smaller and 
with paler feet and under parts and more conspicuous shoulder 
patches; similar in size to C.h. parvulus but darker. 

Cranial characters. — Skull closely similar to that of parvulus; 
smaller than those of heecheyi and C. h. fisheri. 

Color. — Fresh winter pelage (tcpotypes, October) : Head wood 
brown; shoulder patches grayish white, strongl}'^ contrasted with 
the color of the back: dorsal area snuff brown, flecked with light 
pinkish cinnamon: sides more heavily flecked with grayish white; 
feet cartridge buff; under parts grayish white, faintly washed with 
pale pinkish buff; tail black, mixed with white or buffy white. Sum- 
mer pelage (San Pedro Martir Mountains, July) : Dorsal area paler 
(less brownish) than in winter, the general tone on the back near 
wood brown, with a pinkish tinge, the sides more grayish. In cer- 
tain summer specimens in worn pelage — notably one from San 
Telmo, August 22— the general tone of the dorsal area is near cinna- 
mon. In some also, the anterior back, between the white shoulder 
patches, is blackish brown, due in large part to the wearing away of 
the tips of the hairs and exposure of the dark basal portion. 

Molt. — A specimen from the San Pedro Martir Mountains, taken 
June 29, is in badly worn pelage and shows a fresh pelage coming 
in over the anterior half of the back ; several from Trinidad Valley, 
taken July 10 to 16, show a fresh pelage on the rump, the rest of the 
back being much worn. 

Measurements. — Average of 8 adult males from San Pedro Martir Moun- 
tains: Total length. 411.6 (386-442) ; tail vertebrae. 177 (162-196) ; hind foot, 
56.1 (52-62) ; ear from notch (dry), 18.5 (17-20). Average of 11 adult females 
from Hanson Laguna, Trinidad Valley, and San Pedro Martir Mountains : 
Total length, 397 (357-435) ; tail vertebrae. 156.5 (140-186) ; hind foot, 53.7 
(50-57) ; ear from notch (dry), 19 (17-20). Skull: Average of 6 adult males 
from Hanson Lagima. Trinidad Vallev. San Pedro Martir Mountains, and 
San Telmo: Greatest length, 56.8 (54.859.5); palatilar length, 27 (26-28); 
zygomatic breadth, 35.2 (32.8-35.9) ; cranial breadth, 23.5 (22.8-24.4) ; interor- 
bital breadth, 13.7 (11 .-1-14.8) ; postorbital constriction, 16 (15.2-18.1) ; length 



<=9Mus. Vert. Zool. 

f^ Cleveland Mus. Nat. Hist. 

"2 Eighteen in Mus. Vert. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS 159 

of nasals, 20.4 (1&-21.7) ; maxillary tooth row, 11.2 (10.6-12). Average of 
10 adult females from San Pedro Martir Mountains and Hanson Laguna : 
Greatest length, 54.6 (51.6-56.1) ; palatilar length, 25.8 (23.5-27) ; zygomatic 
breadth, 34.2 (32.3-35.2) ; cranial breadth, 23 (22.2-24.7) ; interorbital breadth, 
13.3 (12.2-14.6) ; postorbital constriction, 16.1 (15.6-17.3) ; length of nasals, 
19.5 (17.5-20.6) ; maxillary tooth row, 11.1 (10.4-11.7). 

Remarks. — This is a small, dark race, nearest in general coloration 
to heecheyi, but with more conspicuous white shoulder patches and 
paler under parts. It averages slightly larger in external measure- 
ments than parvulKS, though the skulls of these two races are closely 
s-'imilar. Wliere their ranges meet in the mountains of San Diego 
County, Calif., many intermediate specimens are found. In the 
series examined from Santa Ysabel, Witch Creek, Twin Oaks, 
Jacumba, Nachoguero Valley, and Dulzura, some of the specimens 
are fairly typical of nudipes.^ while others are much paler and might 
almost as well be referred to parvulus. A large series from San 
Ysidro Ranch, on the Mexican boundary line, 19 miles east of the 
Pacific Ocean, are very similar in size and general coloration to 
nudipes., but have somewhat more buffy under parts, thus showing 
approach to heecheyi. The series from around San Diego Bay is 
still more like heecheyi in color, though agreeing with nudipes in 
smaller size of skull and hind feet. A series of 10 specimens from 
Point Loma is about as dark on the upper parts as heecheyi but the 
under parts are decidedly paler. Four specimens from San Diego 
and one from mouth of Tia Juana River agree both in color and size 
with typical nudipes except for somewhat more buify under parts. 
Another individual from Tia Juana River is about as dark as 
heecheyi, both above and below. 

Specimens examined. — Total number, 163, as follows: 

Baja California: Descanso Bay (north side), 1;"^ EI Rayo, Hanson Laguna 
Mountains, 2 ; Ensenada, 1 ; Hanson Laguna, 1 ; Las Eucinos, 1 ; ~ Nacho- 
guero Valley (near Monument 2.";7, Mexican boundary line), 5; San Pedro 
Martir Mountains, 22 (including La Grulla. 2; I'inyon, 2; Rancho San 
Antonio, 9; Rancho Santo Tomas, 1; Vallecitas, 5); San 'JVlnio, 1; San 
Quentin, 3;*^ San Matias Pas.s, 1; San Ysidro Rancli (near Monument 250, 
Mexican boundary line), 15; Tecarte Valley, 1; Trinidad Valley, 6."° 

California: Campo (San Diego County), 1;"^ Chula Vista, 3;"' Cuyamaca 
Mountains (San Diego County), 4;" Dulzura (San Diego County), 16; 
Grapevine Spring (San Diego County), 1;'" Jacumba Springs, 5; Jamul 
Creek (San Diego County), 1; Julian (San Diego County), 8;*" Laguna 
Mountains (San Diego County), 16; Lakeside (San Diego County), 2;"' 
Mountain Spring (4 miles north of Monument 231, ]\Iexican boundary 
line), 8; Oceanside (San Diego County), 2; Pacific Ocean, at Mexican 
boundary line, 1; Point Loma (San Diego County), 10;" San Diego, 6; 
Santa Ysabel (San Diego County). 4: Tia Juana River (mouth). 2; Twin 
Oak.s ( San Diego ( 'ounty ) , 2 : Warner Pass ( San Diego County) , 3 ; " Witch 
Creek (San Diego County), 8." 

CITELLUS BEECIIEYI RUPINARUM Huey 

Catavina Ground Squirisel 

Citellus heecheyi rupinarum Huey, San Diego Soc. Nat. Hist. Trans. 7 : 17, Oct. 
6, 1931. 

Type. — Collected at Catavina, Baja California, Mexico (hititude 
29°54' north, longitude 114°57' west), October 9, 1930, by Laurence 

*' Mus. Vert. Zool. 

•^ San Difigo Soc. Nat. Hist. 

"Field Mus. Nat. Hist. 



IgO NORTH AMERICAN FAUNA [No. 56 

M. Huey ; female subadult, sMn and skull, no. 8251, San Diego Soc. 
Nat. Hist. 

Range. — Deserts of central Baja California, south of the San Pedro 
Martir Mountains ; southern limits unknown (fig. 14). Zonal range: 
Lower Sonoran. 

External characters. — Similar to C. &. nudipes, but paler (less 
brownish) dorsally and without darker area on anterior back; 
shoulder patches less prominent; head slightly paler (less reddish). 
Closely similar to C. h. parvulus., but shoulder patches less distinct 
and front feet apparently darker buff. 

Cranial characters. — Skull very similar to that of nudipes., averag- 
ing slightly smaller and relatively narrower across zygomata. 

Color. — Winter pelage (Oct. 9) : Head pale wood brown or avel- 
laneous; shoulder patches grayish white or creamy white; dorsal 
area sayal brown, flecked with pinkish buff; feet cartridge buff; 
under parts creamy white, washed with pinkish buff on lower abdo- 
men ; tail mixed black and pale pinkish buff. 

Molt. — A specimen from San Fernando, taken September 5, shows 
patches of new pelage on the top of the head and between the shoul- 
ders, the remainder of the pelage being moderately worn. A speci- 
men from Catavina, taken on October 9, has acquired a nearly com- 
plete new pelage except on the nape and shoulders. 

Measurements. — Average of 4 adult females: Total length, 421 (415-425) 
tail vertebrae, 181 (170-188) ; hind foot, 55. Skull: Average of 4 adult 
females: Greatest length, 54.2 (53.2-55.3); palatilar length, 26.1 (25-27) 
zygomatic breadth. 32.9 (.32.3-34.5) ; cranial breadth. 22.9 (22.6-23.5) ; inter 
orbital breadth, 12.2 (11.4-14) ; postorbital constriction, 16.1 (15.7-16.4) 
length of nasals, 18.9 (18.5-19.4) ; maxillary tooth row 11.2 (10.8-11.6). 

Remarks. — This pale subspecies is similar in color to parvulus of 
California; its range is a desert area in Baja California between 
the ranges of nudipes and C . atHcapillus, both of which are darker 
in color. No males of this race have been examined and only four 
females, so that the skull characters and color variations are im- 
perfectly known. 

Specimens examined. — Total number, 4, as follows : 
Baja California: Catavina, 3; " San Fernando, 1. 

CITELLUS BEECHEYI NESIOTICUS Eixiot 

Catalina Ground Sqitireel 

Gitellus nesioticus Elliot, Field Columb. Mus. Pub., Zool. Ser. 3: 263, Mar. 8, 

1904. 
Citellus beecheyi nesioticus Grinnell, Calif. Acad. Sci. Proc. (4) 3: 345, 1913. 
Otospermophihis nesioticus Miller, U. S. Natl. Mus. Bull. 128: 181, 1924. 

Type. — Collected on Santa Catalina Island, Calif., February 8, 
1903, by John Eowley ; male adult, skin and skull, no. 11722, Field 
Mus. Nat. Hist. 

Range. — Catalina Island, Calif, (fig. 14). Zonal range: Upper 
Sonoran. 

External characters. — Similar to G. h. heecheyi., but hind foot 
averaging larger ; coloration very similar, but averaging more gray- 
ish (less brownish) and light shoulder stripes less conspicuous. 

«^ San Diego Soc. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 161 

Cranial characters. — Skull similar to that of heecheyi^ but averag- 
ing larger jnasal branches of premaxillae broader. 

Color. — Winter pelage (February-April) : Head and face pink- 
ish cinnamon or grayish white, more or less darkened ^yhen worn 
by the fuscous bases of the hairs; ears fuscous, broadly bordered 
on posterior portion with drab; upper parts mixed cinnamon buff 
and buffy white, darkened by the fuscous bases of the hairs; shoul- 
ders washed with grayish or buffy white, this wash continuing as an 
indistinct stripe on each side of the dorsal area to the middle of 
the body; sides flecked wdth rather large, irregular spots of white 
or buffy white; tail above, fuscous or fuscous black, mixed with 
buffy white ; tail beneath, pinkish buff, mixed with fuscous black and 
edged with pale buff; feet cartridge buff; under parts pinkish buff 
or warm buff. 

Variation. — ^The type specimen has a large patch of black on the 
forehead, this being the only specimen in the series of 18 examined 
that shows such a marking. Certain specimens in worn winter 
pelage show a large area of fuscous on the back from the occiput to 
the middle of the body. 

Measurements. — Average of 12 adults (4 males, 8 females) from Catalina 
Island: Total length, 451 (432-476) ; tail verterbrae, 172 (154-188) ; hind foot, 

59.1 (5.5-63.5) ; ear from notch (dry), 20.3 (19-21.8). Skull: Average of 4 
adult males from Catalina Island: Greatest length, 60.7 (59.1-61.9) ; palatilar 
length, 29.2 (28-30) ; zygomatic breadth, 38.5 (36.8-40.1) ; cranial breadth, 
24.5 (23.5-25.4) ; interorbital breadth, 15.5 (14.9-16) ; postorbital constriction, 

15.2 (14.7-15.8) ; length of nasals, 22.6 (21.7-23.5) ; maxillary tooth row, 
11.9 (11.8-12). Average of 11 adult females from same locality: Greatest 
length. 58 (56.9-60.3) ; palatilar length, 27.2 (26-28) ; zygomatic breadth, 36.4 
(35-37.5) ; cranial breadth, 23.7 (22.9-24.4) : interorbital breadth, 14.5 (13.5- 
15.9) ; postorbital constriction, 15.3 (14.6-16.2) ; length of nasals, 21.2 (20.6-22) ; 
maxillary tooth row, 11.7 (11.2-12.2). 

Remarks. — This island form is evidently derived from the stock of 
the adjacent mainland, from which it has diverged but slightly. 
Since there is complete intergradation of characters between nesioti- 
cvs and heecheyi.^ and certain specimens from the two series are prac- 
tically identical, the island form is treated as a subspecies. 

Specimens examined. — Total number, 18, from Catalina Island. 

CITELLUS ATRICAT'ILLUS (Bkyant) 
Lower C.\ijforma Rock Squirrel 

Spermophilus granwinrus atricapiUus Bryant, Calif. Acad. Sci. Proc. (2) 2: 

26, June 20, 1889. 
[Citellus variepatus] atricapiUus Elliot, Field Columb. Mus. Pub., Zool. Ser. 

4: 150, 1904. 
Otospermophilus grammurus atricapiUus Miller, U. S. Natl. Mus. Bull. 128: 

180, 1924. 

Type. — None designated; based on 29 specimens from Comondii, 
Baja California, formerly in the collection of the California Acad- 
emy of Sciences, but destroyed by fire in 1906, 

Range. — Southern Baja California, from the Sierra de San Fran- 
cisco (Lat. 28°) south to Comondu (and possibly farther) (fig. 13). 
Zonal range: Lower Sonoran. 

External characters. — Similar to C. heecheyi heecheyi but darker, 
especially on the head and anterior half of the back ; tail averaging 
longer. 

154970—38 11 



IQ2 NORTH AMERICAN FAUNA [No. 56 

Cranial characters. — Skull similar to that of heecheyi, but aver- 
aging slightly smaller. 

Color. — (Topotypes, winter pelage) : Head fuscous black, spar- 
ingly sprinkled with pinkish buff; eye ring buffy white; ears fus- 
cous black, narrowly margined on posterior border with pale buff; 
anterior half of back fuscous black, the sides of neck and shoulders 
tipped with buffy white, leaving a well defined dark triangular patch 
uniting with the color of the head; hairs on posterior back fuscous 
at base, tipped with pinkish cinnamon and pale pinkish buff; front 
feet pale buff ; hind feet pinkish buff ; tail mixed fuscous black and 
pale buff; under parts fuscous, overlaid with pale buff. 

Afolt. — A specimen from Comondu, September 27, had nearly com- 
pleted the molt. New pelage had apparently come in from both 
directions, covering all the body except a small area just behind 
the shoulders. A female from San Ignacio, October 15, shows new 
pelage covering the posterior portion of the body almost to the 
shoulders. 

Measurements. — Average of 12 adults (7 males, 5 females) from type lo- 
cality: Total length, 440.4 (410-465); tail vertebrae, 195 (185-210); hind 
foot, 57.2 (55-60) ; ear from notch (dry), 17.5, 18 (2 specimens). Skull: Aver- 
age of 9 adults (5 males, 4 females) from type locality: Greatest length, 56.3 
(54.8-58.5) ; Palatilar length, 27 (26-28.5) ; zygomatic breadth, 34.5 (33.1-35.7) ; 
cranial breadth, 23.5 (22.6-24.6) ; interorbital breadth, 13 (12-14) ; postorbital 
constriction, 16 (15.1-17) ; length of nasals, 20.2 (19.1-21) ; maxillary tooth row, 
11.5 (11-12). 

Remarks. — Although closely related to C. heecheyi., C. atricapillus 
seems to be a distinct species, distinguished by darker coloration 
of the head and anterior back. The ranges of the two species are 
apparently separated by an area of low country about 40 miles in 
width, where squirrels of this group do not occur. Furthermore, 
the race of heecheyi occurring nearest to the range of atricapillus is 
very much paler (less blackish) and decidedly smaller. 

Specimens examined. — Total number, 38, as follows: 
Baja California: Comondfl, 22; San Ignacio, 15; ** San Pablo, 11. 

NOTOCITELLUS, subgenus nov. 

[Characters and description on p. 44] 

Key to Species and Subspecies 

a^. Cheeks tawny. 

b\ Under parts darker annulatus (p. 163) 

b'. Under parts paler goldmani (p. 164) 

a". Cheeks buffy adocetus (p. 165) 

CITELLUS ANNULATUS (Axtoubon and Bachman) 
[Synonymy under subspecies] 

SpecifiG characters. — Size medium, slightly smaller than C. heech- 
eyi heecheyi; hind foot, 50-&4 mm ; tail, 186-228 ; skull length, 51.6- 
57. Skull similar in general to that of heecheyi., but relatively nar- 
rower across the zygomata, which are less widely expanded at pos- 
terior end; interorbital breadth relatively greater; upper incisors 
shorter and thicker (antero-posterior diameter greater). 

** Eight in collection San Diego Soc. Nat. Hist. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



163 



General form similar to that of G . heecheyi heecheyi but somewhat 
slenderer; ears broader and less pointed; feet and legs slenderer; 
claws on front feet sharper and more curved; tail nearly or quite as 
long as the body, distichous, rather narrow, and not bushy, annulated 
with about 15 blackish bands. 



CITELLUS ANNULATUS ANNULATUS (Aububon and Bachman) 

Ring-tailed Geound Sqihebel 

(Pis. 9; 26, Z); 31, Z)) 

Spermophilus annulatus Audubon and Bachman, Jour. Acad. Nat. Sci. Phila. 

8: 319, 1842. 
Citellus annulatus Merriam, Biol. Soc. Wash. Proc. 16: 79, 1903. 
Otospermophilus annulatus Miller, U. S. Natl. Mus. Bull. 128: 180, 1924. 

Type. — Not designated by number; the type specimen, without as- 
signed locality, was purchased from a dealer by S. F. Baird and 
presented to Audu- 



bon (Baird, 1857, p 
327) ; type locality 
hereby fixed at 
Manzanillo, Colima, 
Mexico. 

Range. — Colima 
and northern Guer- 
rero, Mexico; prob- 
ably also coastal re- 
gion of Michoacan 
(fig. 15). Zonal 
range : Entirely 
Tropical. 

Characters. — As 
given under specific 
characters. Skulls 
of females average 
larger than those of 
males. 

Color. — Upper 
parts, including 
head, nearly uniform 
mixed fuscous black 
and cinnamon buff or 
pale pinkish buff, the 
blackish color often predominating on the head and sometimes on 
portions of the back; chin, throat, and sides of nose and face ochra- 
ceous buff; sides of neck, shoulders, and fore limbs hazel; ears and 
hind legs hazel or tawny ; under parts warm buff or pinkish buff; tail 
above, mixed pinkish buff and black ; tail beneath, hazel. 

Measurements. — Average of 8 adult males from Manzanillo, Colima : Total 
length, 439 (410-470) ; tail vertebrae, 213.4 (187-228) ; bind foot, 58 (54-64) ; 
ear from notch (dry), 14.0 (14-1(V). Average of 9 adult females from 
Manzanillo: Total length, 433.5 (390^70); tail vertebrae, 216.4 (193-238); 
hind foot, 57.1 (54-60); ear from notch (dry), 15.4 (14-18). Skull: Average 
of 7 adult males from Manzanillo: Greatest length, 53.6 (51.6-55.8) ; palatilar 
length, 25.2 (24-26.4) ; zygomatic breadth, 30.5 (28.5-32.2) ; cranial breadth, 




FiGUUK 15. — Distribution of the subspecies of Citellus an- 
nulatus: 1. C. a. goldmani; 2, O. a. annulatus. 



2g4 NORTH AMERICAN FAUNA [No. 56 

21.8 (21.2-22.8) ; interorbital breadth, 13.7 (13.3-15.2) ; postorbital constric- 
tion, 14.4 (13.9-14.9) ; length of nasals, 17.8 (15.9-19.3) ; maxillary tooth row, 
10 (9.6-10.3). Average of 5 adult females from ManzaniUo: Greatest length, 
55.4 (54^57) ; palatilar length, 25.5 (25-26.2) ; zygomatic breadth, 31.2 (30.4- 
32.6) ; cranial breadth, 22.1 (21.1-23) ; interorbital breadth, 14.5 (13.6-15.3) ; 
postorbital constriction, 14.3 (13.3-14.8) ; length of nasals, 18.3 (18-18.8) ; 
maxillary tooth row, 9.9 (9.5-10.2). 

Remarks. — The original specimen on which the species was based 
was purchased from a dealer and was supposed to have come from 
the "western prairies" (Audubon and Bachman, 1851, p. 215). Baird 
(1857, p. 327), however, considered it to be an African species, of 
Sciurus and therefore eliminated it from the list of North American 
mammals. Allen (1877, p. 886), having seen a skin taken by Xantus 
on the plains of Colima, restored the species to the North American 
list, assuming (in the absence of a skull) that it belonged in the 
subgenus Otospermo'philus. Both Bachman and Allen noted the 
resemblance of this animal in some of its characters to the tree 
squirrels {Sciurus). E. W. Nelson and E. A. Goldman, on their 
first trip to Mexico in 1892, obtained 26 specimens in the State of 
Colima, and this fine series has provided the material necessary for 
the present study of the species. This species and G. adocetus are 
the only ground squirrels, excepting G. insulai^s, that are strictly 
tropical in their range. 

The original description differs in some details from the speci- 
mens in hand. Bachman says : "On the under parts, the chin, throat, 
belly, and inner surface of the legs and thighs are white", whereas 
all the specimens examined have these parts ochraceous buff or warm 
buff, except that in a few the belly is buffy white. 

Specimens examined. — Total number, 30, as follows: 

Colima: Armeria, 2; Colima, 3; Hacienda San Antonio (at base of Volcano of 

Colima), 1; ManzaniUo, 20. 
Guerrero: El Naranjo, 3; La Union, 1. 

CITELLUS ANNULATUS GOLDMANI (Mebeiam) 

GrOiLDMAN'S GrOTTND SqUIBREL 

SpermopMlus annulatus goldmani Merriam, Biol. Soc. Wash. Proc. 15: 69, Mar. 

22, 1902. 
Citellus annulatus goldmani Miller and Rehn, Boston Soc. Nat. Hist. Proc. 31 : 

74, 1903. 
OtospermopMlus annulatus goldmani Miller, U. S. Natl. Mus. Bull. 128: 180, 

1924. 

Type. — Collected at Santiago, Nayarit, Mexico, June 18, 1897, by 
E, W. Nelson and E. A. Goldman; female adult, skin and skull, no. 
91259, U. S. Natl. Mus. (Biological Survey collection) (orig. no. 
11223) . 

Range. — Known at present only from the southern part of the 
State of Nayarit on the west coast of Mexico (fig. 15). Zonal range: 
Tropical. 

External characters. — Similar to typical G. a. annulatus., but hind 
foot shorter; upper parts averaging darker (more blackish) and 
under parts paler ; tawny color on sides of head and neck paler and 
less extensive ; hind legs less tawny and more mixed with blackish. 

Cranial characters. — Skull closely similar to that of annulatus. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



165 



Color. — Upper parts fuscous black, sprinkled with ocliraceous 
buff ; sides of head and neck, and fore limbs ocliraceous tawny ; sides 
of body warm buff, mixed with fuscous black; hind limbs tawny 
above, the thighs mixed with fuscous black; throat and under side 
of hind limbs ocliraceous buff ; belly pale pinkish buff ; tail beneath, 
tawny ; above, as in annulatus. 

Measurements. — Average of 6 adult females from Nayarit : Total length, 
415 (383-430) ; tail vertebrae, 204 (186-216) ; bind foot, 51.7 (50-54) ; ear 
from notch, 15.2 (14.5-15.5). Sktill: Average of 5 adult females from Nayarit: 
Greatest length, 53.5 (51.&-55.4) ; palatilar length, 25 (24-26) ; zygomatic 
breadth, 30.4 (29-32.1) ; cranial breadth, 22.2 (21.&-23.1) ; iuterorbital breadth, 
13.5 (13-14.1) ; postorbital constriction, 15.2 (14.5-15.8) ; length of nasals, 17.5 
(16.8-18.5) ; maxillary tooth row, 9.7 (9.3-10.1). 

Remarks. — Goldman's ground squirrel is a slightly darker race of 
C annulatus, occupying an area to the northward of the typical 
subspecies. 

Specimens examined. — Total number, 6, as follows : 

Nayarit: Arroyo de Juan Sanches (about 40 miles southwest of Compostela), 1; 
Compostela, 1 ; San Bias, 2 ; Santiago, 2. 

CITELLUS ADOCETUS Mebeiam 

Lessee Tbopical Gbound Sqtjibrel 

(Pis. 27, E; 32, E) 

Citellus adocetus Merriam, Biol. Soc. Wash. Proc. 16: 79, May 29, 1903. 
Otospermophilus adocetus Miller, U. S. Natl. Mus. Bull. 128 : 179, 1924. 

Type. — Collected at La Salada, 40 miles south of Uruapan, Miclioa- 
can, Mexico, March 17, 1903, by E. W. Nelson and E. A. Goldman ; 

female adult, skin 

and skull, no. 126129, 
U. S. Natl. Mus. (Bi- 
ological Survey col- 
lection) (orig. no. 
16183). 

Range. — Southern 
Michoacan and 
northern Guerrero 
(fig. 16). Zonal 
range : Tropical. 

External charac- 
ters. — Similar to C. 
annulatus but small- 
er and paler (less 
reddish) ; tail with- 
out annulations. 

Cranial c h ar ac- 
ters. — Skull similar 
in shape and denti- 
tion to that of annulatus but much smaller; rostrum shorter and 
broader; iuterorbital region relatively broader; variation in size is 
considerable; -the largest skull in the series is of a female. 

Color. — TF<97*n pelage (March) : Hairs on upper parts fuscous at 
base, tipped with pale pinkish buff or cream color; sides of head and 




FionRE 16. — Distribution of Citellus adocetus. 



IQQ NORTH AMERICAN FAUNA [No. 56 

neck irregularly blotched with ochraceous tawny; front legs pink- 
ish buff or cinnamon buff; hind feet cinnamon buff, the thighs 
ochraceous tawny; tail fuscous or fuscous black, mixed with pale 
pinkish buff or buffy white, the hairs showing three dark bands 
when viewed from beneath, but without annulations above; under 
side of tail shaded with ochraceous tawny toward the tip; under 
parts pinkish buff or warm buff. 

Measurements. — ^Average of 14 adults (10 males, 4 females) from type locality : 
Total length, 335.3 (315-3,53) ; tail vertebrae, 154.6 (138-168) ; hind foot, 46.4 
(43^8) ; ear from notch, 14 (13-15). Skull: Average of 11 adults and subadults 
(6 males, 5 females) : Greatest length, 43.6 (41.6-46.2) ; palatilar length, 20.4 
(19-22) ; zygomatic breadth, 24.6 (23.1-26.2) ; cranial breadth, 19.2 (18.3-20.1) ; 
interorbital breadth, 11.9 (11.5-13.8) ; postorbital contriction, 13.4 (12.6-14.3) ; 
length of nasals, 13.5 (11.1-14.7) ; maxillary tooth row, 8.7 (7.7-9.2). 

Remarks. — This ground squirrel, although clearly rather closely 
related to annulatus, differs from it in many important characters 
of both skin and skull. It occupies a somewhat more arid district, 
farther from the coast than does annulatus. The ranges of the two 
nearly meet and possibly overlap in northern Guerrero. Like an- 
nulatus., the range of this species is entirely within the Tropics. 

Specimens examined. — Total number, 36, as follows : 

Guerrero: La Escondida (about 20 miles southeast of Balsas), 1. 
Michoacan: La Huacana, 2; La Salada, 32 ; Volcan JaruUo, 1. 

Subgenus AMMOSPERMOPHILUS Merriam 

[Cranial characters on p. 44] 
EXTERNAL CHARACTERS 

Upper parts nearly uniform, varying from pinkish buff, vinaceous 
buff, pinkish cinnamon, or vinaceous cinnamon, to wood brown, army 
brown, fawn, drab gray, or mouse gray ; a narrow, white longitudinal 
line on each side of the back, from the shoulders to the rump; tail 
above, mixed black and white, similar beneath, or with a broad white 
or buffy median area. 

PELAGE AND MOLT 

The winter pelage is dense and soft, the summer pelage shorter 
and more wiry. The bases of the hairs are plumbeous, succeeded by 
a rather broad whitish or buffy area, then a narrow brownish area, 
and tipped with white, or varying shades of buff, cinnamon, and gray. 

The squirrels of this group have two molts annually; the spring 
molt takes place between the middle of April and early July — usually 
in May or June — and begins ordinarily on the head and shoulders, 
but sometimes in patches all over the back. The fall molt occurs 
from about the middle of September to the last of October, and pro- 
ceeds from the rump and flanks forward. Several specimens of Citel- 
lus leuxiurus peninsulae from Baja California are unusual in having 
a fresh pelage coming in on the hinder parts, between August 8 
and 23. 



1938] REVISION OF THE GROUND SQUIRRELS 167 

Ket to Species and Subspecies 

o.* Under side of tail with median area white. 
J)} Tail hairs with two black bauds. 

c.^ Upper parts more buffy (pinkish buff to wood brown) nelsoni (p. 182) 

c/ Upper parts less buffy (vinaceous cinnamon to army brown 
or drab gray). 

d.^ Upper parts drab gray interpres (p. 180) 

d.' Upper parts not drab gray. 

e.^ Anterior upper premolar absent or rudimentary- insularis (p. 181) 
e.^ Anterior upper premolar present. 

f.^ Smaller and paler canfieldae (p. 178) 

f.^ Larger and darker. 

g} Rump and thighs army brown penhnulae (p. 176) 

g? Rump and thighs vinaceous cinuamon cxtimus (p. 179) 

6.^ Tail hairs with one black band, 
c* General tone of upper parts vinaceous cinnamon. 

d.^ Upper parts light vinaceous cinnamon pennipcs (p. 175) 

d.^ Upper parts vinaceous cinnamon. 

e.^ Back darkened with fuscous tersus (p. 173) 

e.^ Back not darkened with fuscous cinnamomeus (p. 174) 

c.^ General tone of upper parts pinkish buff leucurus (p. 170) 

a.^ Under side of tail without median white area. 

&.* Colors darker han-isH (p. 167) 

6.* Colors paler saxicola (p. 169) 

CITELLUS HARRISII (Audubon and Bachman) 
[Synonymy under subspecies] 

Specific characters. — Size about as in the larger races of 0. leucurus^ 
but tail averaging longer, 74-91 mm; hind foot, 38-42; skull length, 
38.2^1.2. Skull closely similar to that of C. leucurus cinnamomeus. 
Upper parts in summer pinkish cinnamon, more or less darkened with 
fuscous; in winter, mouse gray; tail above and below, mixed black 
and white (lacking the clear white under surface of leucurus). 

CITELLUS HARRISII HARRISII (Audubon and Bachman) 

Gray-tailed Antelope Squirrel 

(PI. 10) 

Spermophilus harrisii Audubon and Bachman, Quad. North Amer. 3 : 267, 1854. 

Tamias harrisi Merriam, North Amer. Fauna 2 : 19, 1889. 

Anisonyx {Ammospermophilus) harrisii Allen, Amer. Mus. Nat. Hist. Bull. 7: 

240, 1895. 
[Citellus] harrisi Elliot, Field Columb. Mus. Pub., Zool. Ser. 4 : 141, 1904. 
Ammospermophilus harrisii Moarns, U. S. Natl. Mus. Bull. 56 : 303, 1907. 

Type. — None designated; description based on a specimen presented 
lo Audubon by Edward Harris, supposed to have been collected by 
John K. Townsend, but locality unknown. The type locality is hereby 
fixed in the Santa Cruz Valley, Ariz., at the Mexican boundary line.^^^ 

Range. — Greater part of southern, central, and northwestern Ari- 
zona; north to the Colorado liiver, west of longitude 113°; east to 
southwestern New Mexico (Hidalgo County) ; south to southern 
Sonora (Ortiz) ; west to Quitobaquito, on the Mexican boundary line 
(fig. 17). Zonal range: Lower Sonoran. 

"«» Meains (1896, p. 444), in (Inscribing the subspecies saxicola, restricted the name 
harrisii "to the darljcr form, which was found in the Elevated Central Tract, along 
the .Mexican boundary line, from the Santa Cruz Valley westward as far as Uw 
Sonoyta * ♦ *." 



168 



NORTH AMERICAN FAUNA 



INo. 56 



External characters. — Similar to G. leucurus leucurus but larger and 
slightly darker; tail longer and darker, the under surface mixed 
black and white (never clear white). Compared with G. I. cinna- 
TTbomeus: Coloration in winter pelage much more grayish (less vina- 
ceous) ; in summer pelage darker and less vinaceous; tail longer and 
darker beneath. 

Granial characters. — Skull similar to that of leucurus and of cin- 
namoTneus, but averaging larger. 

Golor. — Winter pelage: General tone of upper parts mouse gray, 
the hairs fuscous subterminally, conspicuously tipped with white; 
head and face vinaceous buff or fawn color; shoulders and thighs 

vinaceous fawn; 
front legs and feet 
vinaceous cinnamon; 
hind feet light vina- 
ceous cinnamon, the 
toes pinkish buff; 
tail above and below, 
mixed black and 
white, the hairs with 
a broad subterminal 
band of black and a 
narrower black band 
near the base. Sum- 
mer pelage: Upper 
parts nearly uniform 
light pinkish cinna- 
mon, clearest on the 
shoulders and thighs, 
somewhat darkened 
with fuscous on the 
back. 

Molt. — The spring 
molt occurs in May; 
specimens taken May 
13, 16, and 19, re- 
spectively, are in 
badly worn condi- 
tion, with new hair 
occurring in patches 
all over the body. 
Measurements. — Average of 12 adults (9 males, 3 females) from Tucson and 
Oracle, Ariz. : Total length, 233.8 (225-250) ; tail vertebrae, 82.7 (74^94) ; hind 
foot, 39.7 (38-42). Skull: Average of 8 adult males from Tucson and Santa 
Rita Mountains: Greatest length, 40 (38.8-41.2) ; palatilar length, 18.3 (17-19) ; 
zygomatic breadth, 23.4 (22.8-24.7) ; cranial breadth, 19.1 (18.6-19.5) ; interor- 
bital breadth, 9.9 (9-10.8) ; postorbital constriction, 14.4 (13.9-14.9) ; length of 
nasals, 13.1 (12-13.5) ; maxillary tooth row, 7.2 (6.8-7.5). Average of 7 adult 
females from Tucson, Phoenix, and Roosevelt Lake : Greatest length, 39.4 
(38.4-39.9) ; palatilar length, 18.1 (18-18.5) ; zygomatic breadth, 23 (22.1-23.7) ; 
cranial breadth, 19 (18.5-19.8) ; interorbital breadth, 9.8 (9.4-10.5) ; postor- 
bital constriction, 13.7 (13.1-14.5) ; length of nasals, 12 (11.5-12.7) ; maxillary 
tooth rovr, 7.4 (7-7.8). 

Weight. — Three specimens weighed, respectively, 112, 122, and 139 g. 




Figure 17. — Distribution of Citellus interpres, C. in^ularis, 
and C. nelsoni and of the subspecies of G. leucurus and 
C. harrisii (subgenus AvimospermopMlvs) : 1, C. I. leucu- 
rus; 2, C. I. pennipes ; 3, G. I. cinnamomeus ; 4, G. I. 
tersus; 5, G. I. peninsulae; 6, C. I. canfleldae ; 7, G. I. ex- 
timus; 8, G. insularis; 9, G. h. samicola; 10, G. h. harrisii; 
11, G. interpres; 12, C. nelsoni. 



1938] REVISION OF THE GROUND SQUIRRELS IgQ 

Remarks. — Described by Audubon and Bachman in 1854, this re- 
mained the only recognized species of the group until 1889, when 
Merriam separated leucurus^ which up to that time had been con- 
fused with harrisii. It seems remarkable that a species so distinct 
as this should occupy an area in the middle of the range of the 
group, and separated from its congeners by no seemingly effective 
barriers, at least to the eastward. No reason is apparent why either 
harrisii or 0. interpres should not occupy southwestern New Mexico, 
but so far as known, there is a considerable gap in that region between 
the ranges of these two species. On the west and north, the Colorado 
River with its deep canyon has proved to be effective in separating 
the ranges of harrisii and leucurus. 

Specimens examined. — Total number 217, as follows : 

Arizona: Baboquivari Mountains, 1; Beale Spring (near Kingman), 6; Big 
Sandy Creek (Moliave County), 5; Camp Verde (Yavapai County), 16; 
Congress Junction, 7; Coyote Mountains (Pima County), 1; Dolan Spring 
(12 miles nortliwest of Chloride), 14; Fish Creek (Maricopa County), 4; 
Fort Bowie, 9; Fort Mohave, 5; Gila Mountains (Graham County), 2; 
Graham Mountains (Pinaleno Range), 1; Gold Basin (Mohave County), 3; 
Gold Road (Mohave County), 3 ; ** Hackberry (Mohave County), 1 ; Harqua- 
hala Mountains, 1; H-Bar Ranch (Gila County, 10 miles south of Payson), 
2; Indian Oasis (Pima County), 1; Kingman, 3;'° Kirkland (Yavapai 
County), 4; Klondyke (Graham County), 2; La Oso (Pima County), 1; 
Little Meadows (east side Black Mountains, Mohave County), 6; Mammoth 
(Pinal County), 1; Maricopa County (20 miles southwest of Phoenix), 2;" 
McMillenville (Gila County), 1; Mineral Park (Mohave County), 4; Monte- 
zuma Well (Yavapai County), 4; Mud Spring (18 miles northwest of King- 
man), 7; New River (Maricopa County), 4; Oatman, 1;'" Old Searchlight 
Ferry, Colorado River, 1 ; Oracle (Pinal County), 15 ; Peach Springs (Mohave 
County), 3; Phoenix, 7; Pima County (30 miles south of Tucson), 14;'^ 
Quitobaquito (Pima County), 5; Rice (Gila County), 1; Roosevelt (17 miles 
east), 1; Roosevelt Lake, 3; Salt River (12 miles north of McMillenville), 1; 
Salt River Mountains, 2;'^ Santa Catalina Mountains (mouth of Bear Can- 
yon), 2; Santa Rita Mountains (north base), 4; Sheldon (Greenlee County), 
2; Superior, 2; Tucson, 16; Turkey Creek (east base of Bradshaw Moun- 
tains, Yavapai County), 5; Vail (Pima County), 2;®° Vulture (20 miles 
southwest of Wickenburg), 1; Wickenburg, 1. 

New Mexico: Animas (12 miles northwest, Grant County), 1. 

Sonora: Hermosillo, 1; Magdalena, 3; Ortiz, 1; Poso de Luis (5 miles south of 
Monument 152), 1. 

CITELLUS HARRISII SAXICOLA (Meabns) 
Yuma Antbxopb Sqihrrel 

Spermophilus harrisii saxicolus Mearns, U. S. Natl. Mus. Proc. 18 : 444, May 28, 

1896 (advance sheet published March 25, 1896). 
iCitellus (Spermophilus) harrisi] saxicola Elliot, Field Columb. Mus. Pub., 

Zool. Ser. 4: 142, 1904. 
Ammospermophilus harrisii saxicola (Mearns), U. S. Natl. Mus. Bull. 5^^ fe- 

1907. , length, 

Ammospermophilus harrisii kinoensis Huey, San Die.';;,-; ;' v.iiiiliEJT'<9*'eadth, 18.4 

352, 1937 (Bahia Kino, Sonora, Mexico). , postorbital constriction, 13.9 

7'y^^e._Collected at T' - •---' ' maxillary tooth row, 6.7 (6.1-7). 

Ariz., February 16, 18iTy extensive rancre this race shows relativelv 

and skull, no. 59869, Us from southeastern Oregon appears slightly 

'rom the type region, but the differences are 

7oii'n7*'''lV'^u^^"^- ^/^^- "'^V-n by name. Intergradation with C. I. cinna- 

'" Univ. Michigan Mus. S5oo' A , tt, ii^i t j. j. js 

"Kansa.s Univ. Mus. Nafi Southwestern Utah and the adjacent parts or 

« Field MU.S. Nat. iiist3 of eight specimens from St. George, Utah, some 

are like typical leucurus and others almost like 



170 NORTH AMERICAN FAUNA • [No. 56 

Range. — Southwestern Arizona and northwestern Sonora, from the 
Colorado River east to about longitude 113° (fig. 17). Zonal range: 
Lower Sonoran. 

External characters. — Closely similar to G. h. harrisii but averag- 
ing paler on the head, back, shoulders, and thighs. 

Cranial characters. — Skull very similar to that of harrisii but 
averaging slightly smaller. 

Color. — Winter pelage: General tone of upper parts smoke gray, 
varying to light cinnamon drab, the hairs conspicuously tipped with 
white ; head, face, shoulders, and thighs vinaceoiis buff ; otherwise as 
in harrisii. Summer pelage: General tone of upper parts vinaceous 
fawn, somewhat darkened by the fuscous bases of the hairs, the 
white tips mostly worn off. 

Measurements. — Average of 11 adults (6 males, 5 females) from type lo- 
cality: Total length, 234 (222-245); tail vertebrae, 86.2 (81-92); Mnd foot, 
39.3 (38-41). Skull: Average of 12 adults (8 males, 4 females) from type lo- 
cality: Greatest length, 39.4 (38.2-40.3); palatilar length, 17.8 (16.5-18.8); 
zygomatic breadth, 23 (22.3-23.6) ; cranial breadth, 18.9 (18.6-19.3) ; interor- 
bital breadth, 9.6 (9.1-10.7) ; postorbital constriction, 13.7 (12.4-14.2) ; length of 
nasals, 12.4 (11.3-13.8) ; maxillary tooth row, 6.9 (6.6-7.5). 

Specimens examined. — Total number 65, as follows: 

Arizona: Ajo (10 miles north, Pima County), 6; Castle Dome (Yuma County), 
2; Gila Mountains (Yuma County), 1; Granite Mountains (near Monu- 
ment 187), 2; Parker (Yuma County), 5; Quartzsite (Yuma County), 1; 
Tinajas Altas (Yuma County), 15; Tule Wells (Yuma County), 3; Vicks- 
burg (Yuma County), 6; Yuma, 12. 

Sonora: Bahia Kino, 6; '"" Porto Libertad, 6."'* 

CITELLUS LEUCURUS (Meeeiam) 
[Synonymy under subspecies] 

Specific characters. — Size of C. harrisii or somewhat smaller ; hind 
foot, 85-43 mm; tail, 54-87; skull length, 37-41.8. Skull essentially 
like that of harrisii^ but smaller in some races. General tone of upper 
parts varying in summer pelage from pinkish cinnamon or vinaceous 
cinnamon to cinnamon drab, fawn color, or army brown, the hairs 
more or less tipped with white or buffy white ; in winter pelage more 
grayish, drab gray or mouse gray; tail broadly white or whitish 
below, bordered with fuscous black. 

CITELLUS LEUCURUS LEUCURUS (Mebeiam) 

White-tailed Antelope Sqtjibeel 

(Pis. 10; 27, F; 32, E) 

^^^^^'^(iDMlus harrisii Baird, Mamm. North Amer., p. 313, 1857 (not of Audubon 

^?om"rtS''l""(ii8-North Amer. Rodentia. p. 810, 1877 (not Spenno- 
bital breadth, 9.9 (9-10.8) ; postorbi&fi'ei^-^^.i.ctxoi . 
nasals, 13.1 (12-13.5) ; maxillary tooth rov?, 7.2 (6";^i°^y- „_ ^g„„ 
females from Tucson, Phoenix, and Roosevelt L, r « * VJ . oVn ' -lono 
(38.4-39.9) ; palatilar length, 18.1 (18-18.5) ; zygom^,^- ^e^. ^^±^%f^J|i -.qos 
cranial breadth, 19 (18.5-19.8); interorbital brea "b., Zooi. Ser. d. ^41, lyud 
bital constriction 13.7 (13.1-14.5) ; length of nasah ^ 
tooth row, 7.4 (7-7.8). - ' 

Weight. — Three specimens weighed, respectively. 111,. 



1938] REVISION OF THE GROUND SQUIRRELS 17X 

Type. — Collected in San Gorgonio Pass, Kiverside County, Calif., 
May 16, 1885, by Frank Stephens; male adult, skin and skull, no. 
186466, U. S. Natl. Mus. (-Hif , Merriam collection) (orig. no. 68). 

Range. — Desert regions of southeastern Oregon, southwestern 
Idaho, Nevada, western Utah, southeastern California, and north- 
eastern Baja California; north to northern Malheur County, Oreg., 
and the Snake Kiver Valley, Idaho ; east to the Sevier Eiver Valley, 
Utah; south to San Felipe Bay, Baja California; west to the Mohave 
Desert, Calif, (fig. 17). Zonal range: Upper and Lower Sonoran. 

External characters. — Similar in color to O. harrisii harrisii but 
upper parts and limbs paler, especially in winter pelage ; tail shorter 
and pure white instead of grizzled gray beneath. 

Cranial characters. — Skull closely similar to that of harrisii but 
averaging slightly smaller. 

Color. — Summer pelage: Head and upper parts vinaceous buff; 
eye ring and lateral stripes white ; front and hind limbs light pinkish 
cinnamon, shading to buffy white on the feet ; tail above, mixed black 
and white, except at the base, where it is like the body color; tail 
beneath, clear creamy white, with a subterminal band of black on the 
-sides and tip; under parts white or buffy white. 'Winter pelage 
(November) : Hairs on median dorsal area white at the tips, with a 
subterminal band of fuscous, producing the general tone effect of 
drab gray or pale drab gray, shading to vinaceous buff on the head 
and fore legs ; hind legs vinaceous cinnamon. 

Molt. — The spring molt may begin as early as the middle of April 
or be deferred until July. A specimen taken in the Panamint Moun- 
tains, Calif., April 16, is in much worn pelage, but shows new pelage 
coming in on the head and fore back ; one from Granite Creek, Nev., 
May 18, is in a similar condition of molt; two specimens from 
Cabazon, Calif., May 30 and June 2, show fresh pelage appearing in 
patches all over the upper parts from nose to root of tail. A female 
from Walker Pass, Calif., June 21, had just be^un to molt on the 
head and fore back; a badly worn female specmien from the San 
Jacinto Mountains, Calif., July 6, shows new hair coming in in 
patches all over the body. The fall molt takes place in September 
or October, commencing on the tail and hinder part of body ; a speci- 
men from Whitewater, Calif., September 13, shows new winter pelage 
covering the posterior half of the body; one from Antelope Valley, 
Los Angeles County, Calif., October 17, had completed the fall molt 
except on the head. 

Measuretnents. — Average of 10 adults (5 males, 5 females) from type locality: 
Total length, 216.3 (211-22.3) ; tail vetebrae, 67.5 (^3-71) ; hind foot, 38.3 (37- 
40) ; ear from notch, 9 (8.5-10). Skull: Average of 11 adults (8 males, 3 fe- 
males) from type locality: Greatest length, 3S.S (.37.3^0); palatilar length, 
17.6 (16.8-18.5) ; zygomatic breadth, 22.6 (21.7-23.5) ; cranial breadth, 18.4 
(17.8-19.3) ; interorbital breadth, 9.7 (8.8-10.4) ; postorbital constriction, 13.9 
(13.1-14.9) ; length of nasals, 11.4 (10.7-12) ; maxillary tooth row, 6.7 (6.1-7). 

Remarks. — Over its very extensive rancre this race shows relativelv 
little variation. A series from southeastern Oregon appears slightly 
darker than the series from the type region, but the differences are 
too slight for recognition by name. Intergradation with C. I. cinna- 
m,omeus takes place in soutJiwestern Utah and the adjacent parts of 
Arizona. In a series of eight specimens from St. George, Utah, some 
of the specimens are like typical leucurus and others almost like 



l'J2 NORTH AMERICAN FAUNA [No. 56 

typical cinnamomeus. One from Canaan Spring, Utah, agrees in 
color with leucurus, but has a large skull like that of cinnamomeus. 

This species was confused with harrisii by all writers prior to 1889, 
when Merriam pointed out its characters and named it. 

Specimens examined. — Total number, 584, as follows: 

Arizona: Beaverdam ( =Littlefiel(l, Mohave County), 1; Grand Wash (8 miles 
south of Pakoon Spring, Mohave County), 2; Wolf Hole (6 miles north, 
Mohave County), 2. 

Baja California: San Felipe, IS;''"" San Felipe Bay, 1; San Pedro Martir 
Mountains, 4. 

California: Amedee (Lassen County), 1; Antelope Valley (Los Angeles County), 
1; Argus Mountains, 6; Banning, 4; Barstow, 17; Beckvpith Pass (Lassen 
County), 2; Benton (Mono County), 1;" Bergmann's (25 miles east of 
Temecula, Riverside County), 1;''* Bishop (8 miles west), 1; Borax Flat 
( San Bernardino County), 3; Cabazon (Riverside County), 29; Chucka walla 
Spring (Riverside County), 1; Coast Range Mountains (east base, 5 miles 
north of Monument no. 230), 7; Colorado Desert, 1; Colorado River (oppo- 
site Parker, Ariz.), 5; Coso (Inyo County), 13; Coso Mountains, 2;'" Dag- 
gett (San Bernardino County), 1; Darwin (Inyo County), 1;" Deep Spring 
Valley (Inyo County), 1; Emigrant Spring, Panamint Mountains, 1; 
Funeral Mountains, 1 ; Furnace Creek Ranch, Death Valley, 1 ; Goffs ( San 
Bernardino County), 6; Granite Wells, Mohave Desert, 2; Hesperia (San 
Bernardino County), 1; Hodge (San Bernardino County), 1; Independence 
(Inyo County), 1:^* Inyo Mountains, 7;"'^ Ivanpah (San Bernardino 
County), 4; Jacumba (San Diego County), 1; Kearsarge Pass, 1;'^ Keeler, 
6; ■''"Kern River Valley (near Kernville), 1; Little Lake (Inyo County), 
1 ;" Little Owens Lake, 1 ; Lone Pine, 8 ; Lone Willow Spring ( San Bernar- 
dino County), 9; Long Valley (Lassen County), 1; Lower Alkali Lake 
(Modoc County), 2; Ludlow (San Bernardino County), 2; Mohave, 26; 
Mohave Desert, 7; Mountain Spring (4 miles north of Monument no. 231, 
San Diego County), 14; Needles, 11; Onyx (Kern County), 20; Oro Grande 
(San Bernardino County), 10; Owens Valley, 6; Owens Lake, 5; Palm 
Springs, 5; Panamint Mountains, 42; Panamint Valley, 4; Providence 
Mountains, 3; Radec (12 miles east of Temecula, Riverside County), 5; 
Resting Springs (Inyo County), 15; Saline Valley (Inyo County), 1; Salt 
Wells Valley (Death Valley), 2; San Felipe River (San Diego County), 
4 ; San Felipe Canyon, 1 ; San Gorgonio Pass, 7 ; San Jacinto Mountains 
(Oak Valley), 1; Secret Valley (Lassen County), 2; Shoshone (Inyo 
County), 1;" Smoke Creek (at head, Lassen County), 1; Twelve Mile 
Spring (12 miles north of Resting Springs), 1; Vallecito (San Diego 
County), 2; Victorville, 3; Walker Pass (Kern County), 4; Weldon (Kern 
Coimty), 1;" Whitewater (Riverside County), 4. 

Idaho : Glenns Ferry, 2 ; Murphy, 1. 

Nevada: Alamo, Lincoln County, 1;'^ Ash Spring (Pahranagat Valley), 2;'" Ash 
Meadows (Nye County), IS; Baker Creek (White Pine County), 2;'^^ Black 
Canyon, Colorado River, 3; Blair (Esmeralda County), 1; Candelaria, 5;''* 
Carson City, 1; Cedar Basin (Clark County), 2;^ Charleston Mountains, 4; 
Cloverdale (6 miles south of Golden, Nye County), 2; Desert Valley (23 
miles west of Panaca, Lincoln County), 1;" Elko County, 8 miles south of 
Wendover, Utah, 1;" Esmeralda County, 2;™ Flowing Springs (Humboldt 
County), 2; Granite Creek (Washoe County), 7; Grapevine Mountains, 1; 
Groom Baldy (16 miles east, Lincoln County), 2;" Hot Creek Range (Nye 
County). 1;" Hot Creek Valley (Twin Spring), 1;^* Imlay, 2; Lehmain 
Cave (White Pine County), 1;^^ Little High Rock Canyon (Washoe County), 
1;" Lund (White Pine County), 1:" Meadow Vallev (24 miles south of 
Caliente), 1;'' Millette, 3;"" Nyala (Nye County), 1;" Oasis Valley (Nye 
County), 6; Osobb Valley (Churchill County), 1; Pahranagat Mountains 
(Lincoln County), 1; Pahranagat Valley, 5;" Pahroc Spring (Lincoln 
County). 1; Pahrump Valley (Nye County), 10; Pyramid Lake, 14; Quinn 

■^^Mus. Vert. Zool. 

''*' J. H. Fleming collection. 

's Field Mus. Nat. Hist. 

''^Kansas Univ. Mus. 

™ San Diego Soc. Nat. Hist. 

«« California Inst. Tech. 



1938] REVISION OF THE GROUND SQUIRRELS 173 

Canyon Mountains, 1 ;" Raspberry Creek (near Cosgrave, Pershing County), 
1; Reese River (Nye County), 1; St. Thomas, 1;*" Sharp (Nye County), 4;" 
Silver Peak Mountains, 4; Spring Valley (White Pine County), 2;'" Thorp 
Mill (east base Grapevine Mountains), 2; Timpahute Mountains, 1; Virgin 
Valley (Humboldt County), 1;'^ Virginia Mountains, 2; Vegas Valley (Lin- 
coln County), 3; Wadsworth, 6; Washoe Lake, 1; White River Valley (Nye 
County ) , 1 ;'^ Winnemucca Lake, 10. 

Oregon: Adel (Lake County), 4; Rome (Malheur County), 1; South Warner 
Lake, 1; Tumtum Lake, 6; Vale, 1; Warner Valley, 1; Watson (Malheur 
County), 10. 

Utah: Canaan Spring (Washington County, near Arizona line), 1; Clear Creek 
(Sevier County), 1; Elberta (Utah County), 2;^" Esealante, 1;™^ Fillmore, 
1; Hebron (Washington County), 4; Junction (Piute County), 1; Marysvale, 
2; Monroe, 2;" Nephi, 1; Parowan, 1;''* Promontory Point (Box Elder 
County), 1; St. George, 9; Sevier River (10 miles south of Panguitch), 1; 
Toquerville, 2. 

CITELLUS LEUCURUS TERSUS (Goldman) 

Gband Canyon Antexope Squirrel 

AmmospermophUns Jeiicurus tersus Goldman, Jour. Wash. Acad. Sci. 19: 435, 
Nov. 19, 1929. 

Type. — Collected in Prospect Valley, Grand Canyon, Hiialpai In- 
dian Reservation, Ariz, (4,500 feet altitude) , October 3, 1913, by E, A. 
Goldman ; male subadult, skin and skull, no. 202645, U. S. Natl. Mus. 
(Biological Survey collection) (orig. no. 22269). 

Range. — Terraces on southern side of Grand Canyon, in the Hual- 
pai Indian Reservation, Ariz. (fig. 17). Zonal Range: Upper 
Sonoran. 

External characters. — Similar in size to C. I. leucunts, but upper 
parts darker (more brownish, less grayish), especially on the rump 
and lower back. Compared with C. I. cinnamomeiis: Upper parts 
more brownish (less pinkish or cinnamon) ; size smaller. 

Cranial characters. — Skull similar to that of leucurus., but averag- 
ing slightly smaller in length and zygomatic breadth; nasals about 
same length, but slightly narrower. 

Color. — Winter pelage: Upper parts fawn color or army brown; 
shoulders and fore back heavily sprinkled with whitish hairs; hinder 
back, rump, and thighs darker; feet whitish, washed with light vina- 
ceous cinnamon; under parts creamy white; tail as in leucurus. Full 
summer pelage not seen ; in a worn specimen taken October 3 the head 
and fore back are pinkish cinnamon, the rest of the body in winter 
pelage. 

Molt. — The fall molt occurs in late September; a specimen taken 
September 26 has acquired winter pelage over the entire body except- 
ing the head ; others taken October 3 still retain worn summer pelage 
on the anterior half of the body, the rest being in full winter pelage. 

Measurements. — Average of 9 adults from type locality : Total length, 204 
(19^214) ; tail vertebrae, 62 (54-72) ; hind foot, 39 (3S-40) ; ear from notch, 
8 (7-9). Skull: Average of 10 adults (5 males, 5 females) ; Greatest length, 
37.5 (37-39.1) ; palatilar length, 17 (16.5-17.5) ; zygomatic breadth, 21.9 (21.3- 
22.6) ; cranial breadth, 18.5 (18-19) ; interorbital breadth, 9.3 (8.6-9.6) ; post- 
orbital constriction, 13.7 (13.3-14.3) ; length of nasals, 11.6 (11.2-12.5) ; maxil- 
lary tooth row, 6.7 (6.S-7.4). 



•'••' Mu.s. Vert. Zool. 
■" Tltnh State Agr. College. 
« Cleveland Mus. Nat. Hist. 
»^ California Inst. Toch. 
•"» Brigham Young Univ. 



174 NORTH AMERICAN FAUNA [No. 56 

Remarks. — Goldman (1929, p. 435), has described the habitat of 
this race as follows: 

In the Grand Canyon of the Colorado River, which bisects the high plateau 
region of northern Arizona, antelope squirrels are restricted mainly to the 
broader terraces bordering the inner gorge. These terraces are cut at frequent 
intervals by side canyons, some of which extend with sheer walls to the nearly 
or quite precipitous outer rim of the main canyon. The higher parts of the 
Coconino Plateau along Grand Canyon are unsuited to the needs of antelope 
squirrels and the side canyons mentioned, while not absolute barriers at their 
heads, evidently tend to break the continuity of range within the main canyon. 

Specimens examined. — Total number, 10, from type locality. 

CITELLUS LEUCURUS CINNAMOMEUS (Merbiam) 

RusTT Antelope Squikrel 

Tamias leucurus cinnamomeus Merriam, North Amer. Fauna 3 : 52, Sept. 11, 

1890. 
Anisonyx (Animosperniophilus) leucurus cinnamomeus Allen, Amer. Mus. Nat. 

Hist. Bull. 7: 240, 1895. 
[Spermopliilus leucurus] cinnamomeus Elliot, Field Columb. Mus. Pub., Zool. Ser. 

2 : 86, 1901. 
Citellus leucurus cinnamomeus Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 

97, 1905. 
AmmospermopMlus leucurus cinnamomeus Mearns, U. S. Natl. Mus. Bull. 56: 

299, 1907. 

Type. — Collected at Echo Cliffs, Painted Desert, Ariz., September 
22, 1889, by C, Hart Merriam and Vernon Bailey; female subadult, 
skin and skull, no. f||-|-, U. S. Natl. Mus. (Biological Survey collec- 
tion) (orig. no. 510). 

Range. — Northeastern Arizona, southern "Utah, and southwestern 
Colorado ; north to Mount Carmel, Utah and Coventry, Colo. ; south 
to Taylor, Ariz. (fig. 17). Zonal range: Mainly Upper Sonoran. 

External characters. — Similar to G. I. leucurtis., but coloration of 
upper parts darker and more reddish (less grayish) ; hind legs darker. 

Cranial characters. — Skull similar to that of leucurus but averag- 
ing slightly larger, with longer nasals. 

Color. — Winter pelage: General tone of upper parts vinaceous 
cinnamon, more or less darkened, especially on the hinder back and 
rump by mikado brown, which forms a subterminal band on most 
of the hairs ; many of the hairs are tipped with white, most strongly 
on the fore back; sides of head and neck washed with fuscous; eye 
ring buffy w^hite; lateral stripes creamy white; hind legs vinaceous 
cinnamon to army brown, the feet buffy white, washed with pinkish 
cinnamon ; front legs similar, but paler ; tail above, mixed black and 
white; tail beneath, creamy white, bordered with black; under parts 
white, washed with cartridge buff. Summer pelage: Upper parts 
nearly uniform vinaceous cinnamon ; feet light vinaceous cinnamon ; 
otherwise as in winter. 

Molt. — A specimen from the Grand Canyon, Ariz., taken May 27, 
shows new pelage appearing on the head and nape; one from the 
Navajo Indian Eeservation, June 14, had nearly completed the spring 
molt, new pelage covering all of the body except the rump and 
hind legs. 

Measurements. — ^Average of 12 adults (7 males, 5 females) from the Painted 
Desert and Keams Canyon : Total length, 225.8 (215-238) ; tail vertebrae, 73 
(64-79) ; hind foot, 40 (39-43). STcull: Average of 8 adults (4 males, 4 females) 
from the Painted Desert: Greatest length, 89.3 (38.9-39.7); palatilar length. 



1938] REVISION OF THE GROUND SQUIRRELS 175 

17.3 (16.5-18) ; zygomatic breadth, 23 (22-23.7) ; cranial breadth, 19.1 (18.5- 
19.7) ; interorbital breadth, 9.5 (9.3-9.8) ; postorbital constriction, 14.1 (13.6- 
14.5) ; length of nasals, 12.4 (11.9-13) ; maxillary tooth row, 7.2 (7.1-7.8). 

Remarks. — This richly colored race has a much more restricted dis- 
tribution than leuGurus, occurring chiefly in the deserts of north- 
eastern Arizona. Specimens from Fredonia, in extreme northern Ar- 
izona, do not differ appreciably from those living on the south side 
of the Colorado River; at Kanab and Mount Carmel, Utah, however, 
the animals are paler and show evidence of intergradation with 
leucurus. The series from Bluff City and Noland Ranch, on the 
San Juan River, southeastern Utah, is typical. One specimen from 
Coventry, Colo., seems referable to cinnamorneus, although it appears 
to represent an intrusion into the range of C. I. pennipes. 

Specimens examhied. — Total number, 110, as follows : 

Arizona: Apache County (near Keams Canyon), 3; Aztec Tank (Coconino 
County), 5; Cedar Ranch Wash (Locket Tank, Coconino County), 2; 
Deadman Wash (Coconino County), 1; Fredonia, 4; Grand Canyon, 9 
(Indian Gardens, 6; Pipe Creek, 2; Bass Camp, 1): Holbrook (fs^ivajo 
County), 9; Jacobs Pool (Coconino County), 4; Kayenta (Navajo Indian 
Reservation), 1; Keams Canyon (Navajo County), 11; Lees Ferry (north 
side), 3; Lukachukai (Navajo Indian Reservation), 2; O'Leary Peak 
(6,000 feet altitude), 1; Oraibi (Hopi Indian Reservation), 4; Painted 
Desert, 8; Taylor (Navajo County), 1; Tuba (Coconino County), 5; 
Winslow, 12; Zuni River (Apache County), 1. 

Colorado: Ashbaugh's Ranch (near McElmo, Montezuma County), 1; Cov- 
entry, 1. 

Utah : Bluff City (San Juan River) , 6 ; Kanab, 6 ; Mount Carmel (Kane County) , 
3; Noland Ranch (San Juan River), 2; Notom (Wayne County), 2;^" 
Willow Tank Spring (Kane County), 3.*"" 

CITELLUS LEUCURUS PENNIPES (Howell) 

Colorado Antbxope Squierel 

Ammospermophilus leucurus pennipes Howell, Jour. Mammal. 12: 162, May 14, 
1931. 

Type. — Collected at Grand Junction, Colo., November 11, 1895, by 
A. H. Howell; female adult, skin and skull, no. 75683, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 494). 

Range. — The Colorado Valley and its tributaries (except the San 
Juan) in western Colorado, eastern Utah, and northwestern New 
Mexico ; north to Vernal, Utah and Rangely, Colo. : west to Thurber, 
Utah; south to Socorro Mountains, N. Mex. (fig. 17). Zonal range: 
Upper Sonoran. 

External characters. — Similar to G. I. cinno/inomeus^ but upper 
parts in winter pelage more grayish (less vinaceous) and in summer 
pelage darker and more brownish. Compared with C . I. leucurus: 
upper parts in whiter pelage averaging more vinaceous (less gray- 
isli) in general tone; in summer pelage decidedly more vinaceous. 

Cranial characters. — Skull similar to that of cinnamorneus but 
averaging slightly larger; decidedly larger than that of leucurus. 

Color. — Winter pelage (November) : Upper parts light vinaceous 
cinnamon, the hairs on the median dorsal area from crown to rump 
extensively tipped with white; flanks and hind legs vinaceous cinna- 

wh Brlgham Young Univ. 



I'^Q NORTH AMERICAN FAUNA [No. 56 

iiion, shading to pale pinkish buff on the hind feet; front feet sim- 
ilar ; lateral stripes creamy white ; tail above, mixed black and gray- 
ish white, shaded with the body color at the base, the hairs showing 
a broad subterminal band of black; tail beneath, creamy white, bor- 
dered with black ; under parts white, tinged with pale buff. Summer 
pelage (June) : Upper parts light pinkish cinnamon, more or less 
darkened on the median dorsal area by the fuscous bases of the hairs 
and shaded on the shoulders by a wash of white; flanks and hind 
legs light vinaceous cinnamon, shading to pinkish buff on the feet; 
under parts buffy white ; tail as in the winter pelage. 

AIoU. — A specimen from Huntington, Utah, taken in April, shows 
the summer pelage coming in on the head and fore back. 

Measurements. — Average of 10 adults (4 males, 6 females) from type locality: 
Total length, 226.6 (220-239) ; tail vertebrae, 68.8 (60-76) ; hind foot, 39 
(38--41) ; ear from notch (dry), 8.7 (7-10). Skull: Average of 9 adults (5 males, 
4 females) from type locality: Greatest length, 40.2 (38.9-41.8); palatilar 
length, 18.2 (17.8-18.6) ; zygomatic breadth, 23.2 (22.6-24.2) ; cranial breadth, 
18.9 (18.4-19.5) ; interorbital breadth, 9.6 (9.3-10.1) ; postorbital constriction, 
13.7 (13.1-14.5) ; length of nasals, 12.7 (12-13.7) ; maxillary tooth row, 7.1 
(6.3-7.5). 

Remarks. — This race, apparently most closely related to cinna- 
momeus, differs from it in being less strongly vinaceous in color; in 
this respect it approaches leucurus but it has a decidedly larger skull. 
A series in full winter pelage from Fruitland and Shiprock, N. Mex., 
agrees closely with typical pennipes, and differs markedly from the 
series of cinnamomeus from Bluff City, Utah, lower down in the same 
valley. Specimens from Jemez, Rio Puerco, and Socorro Mountains, 
N. Mex., seem referable to pennipes and show no approach to G. in- 
terpres., which occurs on the eastern side of the Rio Grande Valley. 

Specimens examined. — Total number, 72, as follows : 

Colorado: Fruita, 1; Grand Junction, 22; Hotchkiss, 2; Rangely (Rio Blanco 
County), 1 ; White River (20 miles east of Rangely), 2. 

New Mexico: Albuquerque (35 miles west), 1; Fruitland (San Juan County), 
12; Jemez (Sandoval County), 2; Rio Puerco (Valencia County), 1; Ship- 
rock (San Juan County), 2; Socorro Mountains (10 miles northwest), 1. 

Utah: Emery County (near Huntington), 1; Henry Mountains, 2; Jimction of 
Green and White Rivers, 1;*^ Lyman (Wayne County), 1; " Ouray (8 and 
15 miles southwest), 11;" Thurber (Wayne County), 4; Uncompahgre 
Indian Reservation, 1 ; *^ Vernal, 4. 

CITELLUS LEUCURUS PENINSULAS (Allen) 
Western Peninsular Antelope SQiniREEii 

Tamias leucurus peninsulae Allen, Amer. Mus. Nat. Hist. Bull. 5 : 197, Aug. IS, 

1893. 
Citellus leucurus peninsulae Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 211, 

1903. 
AmmospermopMlus leucurus peninsulae Mearns, U. S. Natl. Mus. Bull. 56: 299, 

1907. 

Type. — Collected at San Telmo, Baja California, April 30, 1893, by 
A. W. Anthony; male adult, skin and skull, no. If-Jf, Amer. Mus. 
Nat. Hist. (orig. no. 8). 

^ Carnegie Mus. 

82 Utah State Agr. College. 

88 Field Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 177 

Range. — ^Western side of the Baja California Peninsula; east to 
the base of the San Pedro Martir Mountains ; south to San Fernando 
(fig. 17). Zonal range: Upper Sonoran. 

External characters. — Similar to G. I. leucurus^ but darker through- 
out ; the upper parts a deeper shade of vinaceous and with more black 
intermixed ; feet darker cinnamon ; tail more blackish above and more 
buffy beneath, the hairs having two black bands. 

Cranial characters. — Skull similar to that of leucurus, but averag- 
ing larger. 

Color. — Summer pelage (August 22) : Head and upper parts pink- 
ish cinnamon, more or less heavily mixed with black, the general tone 
near army brown; eye ring and lateral stripes creamy white; front 
legs and feet pinkish cinnamon or mikado brown; hind legs mikado 
brown or vinaceous cinnamon, shading to light pinkish cinnamon on 
the feet; tail above, cinnamon at base, the rest black, slightly tipped 
with grayish white; tail beneath, cartridge buff or buffy white, bor- 
dered with black and tipped with grayish white ; under parts car- 
tridge buff or buffy white. 

Variation. — One topotype (Aug. 21) has the nape and shoulders 
rather heavily sprinkled with grayish white. Some specimens have 
considerable black on the terminal portion of the tail, due to the 
presence of the band of black near the base of the hairs. Winter (?) 
pelage: Specimens taken August 21 to 23 have acquired a fresh pe- 
lage covering the posterior half of the body ; the general tone is near 
army brown, shading to vinaceous cinnamon on the legs and to light 
vinaceous cinnamon or pinkish buff on the feet. 

Molt. — An adult female taken August 21 at San Telmo shows a 
fresh pelage covering the posterior half of the back, similar in color to 
the summer pelage. An adult male from San Quintin, August 8, 
shows a fresh pelage appearing on the rump ; an adult female from 
the same locality, August 23, is in similar condition, the new i)elage 
covering nearly the posterior half of the body. 

Measurements. — Average of 5 adults (2 males, 3 females), from type locality: 
Total length, 224 (21J>-230) ; tail vertebrae, 74 (72-77) ; hind foot, 39.1 (38.5-40) ; 
ear from notch (dry), 8 (7-9). Skull: Average of 5 adults from type locality: 
Greatest length, 39.9 (38.&-41.4) ; palatilar length, 18 (17-19) ; zygomatic breadth, 
23.2 (22.2-23.8) ; cranial breadth, 19 (18.7-19.3) ; interorbital breadth, 9.8 (9.6- 
10) ; postorbital constriction, 14.8 (14-15.2) ; length of nasals, 12.2 (11.3-12.5) ; 
maxillary tooth row, 7.4 (7-7.7). 

Remarks. — This subspecies has a rather limited range on the west- 
ern side of the Baja California Peninsula. It is closely related to 
C. I. extimus, which occupies the southern end of the peninsula, but 
its range is separated from that of extimus by a desert area occupied 
by C. I. can'jleldae. 

Specimens examined. — Total number, 44, as follows : 

Baja California: Agua Escondido (near Hanson Laguna), 2;*' La Huerta (west 
base Hanson Laguna Mountains), 1; Rancho La Progresa, 2;" Rancho 
Viejo (15 miles east of Alamo), 2; Rosario, 10;'^*^ San Fernando, 2; San 
Quintin, 15; San Rafael Valley (20 miles east of Ojos Negros), 1; San 
Telmo, 8; Trinidad Valley, 1." 



** Amer. Mus. Nat. Hist. 
^ Mus. Comp. Zool. 
*« Los Angeles Museum. 
«7 Field ^fu8. Nat. Hist. 

154970—38 12 



I'Jg NORTH AMERICAN FAUNA [No. 5G 

CITELLUS LEUCURUS CANFIELDAE (Huey) 

MiD-PENINSULAB AnTELOPE SQUIEREL 

Ammospermophilus leucurus canfieldae Huey, San Diego Soc. Nat. Hist. Trans. 5 : 
243, Feb. 27, 1929. 

Type. — Collected at Piinta Prieta, Baja California, Mexico (lat. 
28°56' north; long. 114°12' west) , February 14, 1928, by Laurence M. 
Huey ; male adult, skin and skull, no. 6783, San Diego Soc, Nat. Hist. 

Range. — Desert region of central Baja California, from about lati- 
tude 30° southward over the Vizcaino Desert to about latitude 28° 
(fig, 17), Zonal range: Lower Sonoran, 

External characters. — Similar in color to C. I. leucurus but darker 
on body and limbs; under side of tail with more black, due to the 
presence of an additional black band on some of the hairs. Compared 
with G. I. peninsulae and O. I. exthnus^ the color is paler. 

Cranial characters. — Skull closely similar to that of leucurus., but 
with relatively wider interpterygoid fossa; smaller than that of 
peninsulae. 

Color. — 'Winter pelage (February) : Nose and front of face cinna- 
mon ; sides of head grayish white, shaded with fuscous ; hairs on up- 
per parts, from crown to rump, fuscous subterminally, tipped with 
grayish white on fore back and with light pinkish cinnamon on middle 
and hinder back (the general tone near cinnamon drab) ; lateral 
stripes clear white; flanks and hind legs, shoulders, and fore legs, 
vinaceous cinnamon, shading to light pinkish cinnamon on the feet; 
tail above, like the back for about one-third of its length, then mixed 
black and grayish white; tail beneath, creamy white in the center, 
somewhat darkened by the presence of a narrow band of black on 
the middle portion of some of the hairs; all the hairs having a broad 
subterminal band of black, tipped with white; mider parts creamy 
white. 'Worn summer pelage (September) : Upper parts and feet 
nearly uniform pinkish cinnamon or light pinkish cinnamon. Young 
(Sept, 9) : Similar to summer adults, but shoulders and fore back 
heavily sprinkled with white. 

Molt. — A much worn young individual taken September 16 at Cala- 
mahue shows new pelage covering the head; an adult from Santa 
Domingo, September 27, had acquired the winter pelage over the 
posterior half of the body. 

Measurements.- — Average of 5 adults (2 males, 3 females) : Total length, 220.6 
(215-226) ; tail vertebrae, 70.8 (66-78) ; hind foot, 36 (35-38) ; ear from notch 
(dry), 8.2 (8-8.5). Skull: Average of 6 adults (3 males, 3 females) : Greatest 
length, 38.5 (37.5-39) ; palatilar length, 17.2 (17-17.5) ; zygomatic breadth, 22.8 
(21.9-22.7) ; cranial breadth, 18.3 (18-19) ; interorbital breadth, 9.3 (8.9-10) ; 
postorbital constriction, 13.6 (12.9-14.3) ; length of nasals, 11.7 (11-12.6) ; max- 
illary tooth row, 6.9 (6.5-7.1). 

RemarTts. — This race, occupying a desert area in the middle of the 
Baja California Peninsula, is intermediate between leucurus on the 
north and extimus on the south, with both of which it intergrades 
where their ranges meet. 

Specimens examined. — Total number, 15, as follows : 

Baja California: Calamahue, 4; Campo Los Angeles, 2;^ Jaraguay (58 miles 
southeast of San Fernando), 2; Mesquital, 1;*^ Punta Prieta, 2;^ San An- 
dres, 1;*° Santo Domingo, 2; Yubay (30 miles southeast of Calamahue), 1. 



«8 San Diego Soc. Nat. Hist, 
*^Mus. Comp. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS 179 

CITELLUS LEUCURUS EXTIMUS (Nelson and Goldman) 

SoLTHEKN Peninsular Antelope Squirrel 

Ammospermophilus leucurus evtimus Nelson and Goldman, Jour. Wash. Acad. 
Sci. 19: 281, July 19, 1929. 

Type. — Collected at Saccaton (15 miles north of Cape San Lucas), 
Baja California, Mexico, December 29, 1905, by E. W. Nelson and 
E. A. Goldman; female adult, skin and skull, no. 146587, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 18805). 

Range. — Southern part of the Baja California Peninsula, from 
Cape San Lucas north to about latitude 28° (except the Vizcaino 
Desert) ; ranging from sea level to about 1,000 feet altitude on the 
slopes of the mountains (fig. 17). Zonal range: Lower Sonoran and 
Tropical. 

External characters. — Similar to C. I. canfleJdae., but larger, and 
darker (more brownish), especially on the head, rump, and thighs. 
Similar to G. I. peninsulae in color, but slightly paler, the rump and 
thighs more vinaceous in tone rather than ochraceous. 

Vranial characters. — Skull larger than that of canfieldae and 0. I. 
leucurus., with relatively smaller bullae; closely similar to that of 
peninsulae., the bullae averaging slightly broader (less wheel shaped). 

Color. — Winter pelage: Top of head vinaceous cinnamon, shaded 
with fuscous ; sides of head grayish white, shaded with fuscous ; eye 
ring white; upper parts light vinaceous cinnamon, shaded with gray- 
ish white on shoulders and fore back and heavily mixed with fuscous 
on middle and hinder back; lateral stripes creamy white; hips and 
thighs vinaceous cinnamon; fore and hind feet light vinaceous cin- 
namon ; tail above, mixed black and buflfy white ; tail beneath, grayish 
white or cartridge buff, bordered with black and tipped with buffy 
white; under parts buffy white. Summer pelage (September) : Up- 
per parts vinaceous cinnamon, darkest on the head and rump, be- 
coming light vinaceous cinnamon on the shoulders and fore legs. 

Molt. — No specimens are available to show the progress of the 
spring molt; the fall molt begins in October on the hinder part of 
the body; a specimen from El Potrero, October 31, has acquired new 
pelage over the whole body excepting the head ; one from Comondu, 
November 7, is in the same condition, the head retaining old worn 
pelage. 

Measurements. — Average of 10 adults from southern Baja California (Co- 
mondti to Cape San Lucas) : Total length, 219.8 (208-237) ; tail vertebrae, 79 
(70-87) ; hind foot, 37.2 (3;5-38) ; ear from notch, 8.9 (8-10). SJcull: Average 
of 11 adults from Saccaton and Cape San Lucas : Greatest length, 40.3 (39- 
41.6) ; palatilar length, 19 (17.5-20) ; zygomatic breadth, 23 (22.5-23.8) ; cranial 
breadth, 18.6 (18.2-19) ; interorbital breadth, 9.9 (9.2-10.3) ; postorbital con- 
striction. 13.5 (12.7-14.9) ; length of nasals, 12.9 (11.5-13.7) ; maxillary tooth 
row, 7 (6.3-7.6). 

Remarks. — This race, occupying the southern end of the peninsula 
of Baja California, is most nearly related to peninsulae of the north- 
west coast region ; their ranges are separated, however, by the range 
of canfieldae, a smaller and paler race occupying the desert region in 
the middle of the peninsula. 



IgQ NORTH AMERICAN FAUNA [No. 56 

SpeciTnens examined. — Total number, 70, as follows: 

Baja California: Aguaje de San Estaban, 1; Cape San Lucas, 24; Comondii, 
9; El Potrero, 2; La Paz, 4; Matancita, 1; Saccaton (15 miles north of 
Cape San Lucas), 4; San Bruno, 1; San Ignacio, 6; San Jose (30 miles 
north of La Purisima), 2; San Jose del Cabo, 5; San Juanico Bay, 2;"° 
San Pablo, 6; Santana, 3." 

CITELLUS INTERPRES (Mebbiam) 

Texas Antelopb Sqxjirkel 

TamicCs interpres Merriam, North Amer. Fauna 4 : 21, Oct. 8, 1890. 
SpermopMlus interpres Bryant, Zoe 3 : 208, October 1892. 
Witellus] interpres Elliot, Field Columb. Mus. Pub., Zool. Ser. 4: 143, 1904. 
Ammospermophilus interpres Bailey, North Amer. Fauna 25 : 81, 1905. 
Ammospermophilus leucurus interpres Mearns, U. S. Natl. Mus. Bull. 56 : 301, 
1907. 

Type. — Collected at El Paso, Tex., December 10, 1889, by Vernon 
Bailey; female adult, skin and skull, no. |f^^, U. S. Natl. Mus. 
(Biological Survey collection) (orig. no. 762). 

Range. — ^Western Texas and south-central New Mexico, north to 
the Manzano Mountains; east to the Pecos Eiver Valley and the 
Castle Mountains, Tex.; west to the eastern side of the Rio Grande 
Valley in New Mexico; south to Jaral, Coahuila (fig. 17). Zoned 
range: Lower Sonoran. 

^External characters. — Closely similar in winter pelage to G . leucurus 
leucurus.^ but differing from it in having an additional black band 
on the tail hairs ; coloration much paler and more grayish (less red- 
dish) than in G. I. cinnamomeus. 

Granial characters. — Skull similar to that of cinnamomeus but 
with superior outline flatter and brain case shallower ; nasals broader 
at posterior end, truncated squarely on a line with the ends of the 
premaxillae ; upper tooth row shorter. 

Golor. — Winter pelage: Upper parts light drab or drab gray (the 
tips of the hairs white, with a subterminal band of fuscous) ; nose 
and front of face washed with pinkish cinnamon; eye ring white; 
front and hind legs, and hips, pinkish cinnamon or light pinkish cin- 
namon; feet light pinkish cinnamon, shaded with buffy white 5 tail 
above, mixed black and white, with a patch of light pinkish cinna- 
mon at the proximal end ; tail beneath, creamy white, bordered with 
black and with a free black band on the middle portion of some of 
the hairs ; under parts white. 

Variation. — Two specimens from the Manzano Mountains, N. Mex., 
are slightly darker (pale fawn color) on the rump and hind legs. 

Molt. — A specimen taken at Boquillas, Tex., May 23, is in a badly 
worn pelage, and shows new hair coming in on the head and fore 
back. 

Measurements. — Average of 10 adults (8 males, 2 females) from El Paso, 
Tex. : Total length, 226 (220-235) ; tail vertebrae, 74.2 (68-84) ; hind foot, 37.8 
(36-40); ear from notch (dry), 9.8 (8-11). Skull: Average of 14 adults (8 
males, 6 females) from El Paso: Greatest length, 39.3 (37.7-^0.5); palatilar 
length, 17.3 (16-18.2) ; zygomatic breadth, 22.7 (21.5-23.8) ; cranial breadth, 
18.9 (lS-19.6) ; interorbital breadth, 9.9 (9.4-10.5) ; postorbital constriction, 14.5 
(13.8-15.3) ; length of nasals, 12.6 (11.8-13.8) ; maxillary tooth row, 6.6 (6.4^6.9), 



»oAmer. Mus. Nat. Hist. 
^ Mus. Comp. Zool. 



1938] REVISION OF THE GROUND SQUIRRELS Igl 

Remarks. — The range of this species seems to be restricted to the 
region east and north of the Rio Grande. There is no evidence of 
intergradation with cinnamomeus ; the latter is known from speci- 
mens taken in the Socorro Mountains, a few miles west of the Rio 
Grande, whereas inferpres is known from the eastern side of the river, 
at a point nearly opposite. 

/Specimens examined. — Total number, 62, as follows : 

Coahuila: Jaral, l.°^ 

New Mexico: Manzano Mountains (east foothills), 2; Organ Mountains, 1;*' 

San Andres Mountains, 11 ; Socorro (10 miles northeast), 1. 
Texas: Boquillas, 3; Castle Mountains (Crockett County), 1; El Paso, 32; Fort 

Lancaster (near Sheffield, Crockett County), 1; Franklin Mountains (10 

miles north of El Paso), 6; Guadalupe Mountains (south end), 1; High 

Bridge, Pecos River (mouth), 1; Sierra Blanca, 1. 

CITELLUS INSULARIS (Nelson and Goldman) 
EspiKiTU Santo Antelope Squirrel 

Ammospermophilus leucuriis insularis Nelson and Goldman, Biol. Soc. Wash. 

Proc. 22 : 24, Mar. 10, 1909. 
Citellus leucurus insularis Elliot, Sup. Check-list Mammals North Amer., p. 

28, 1917. 

Type. — Collected on Espiritu Santo Island, Gulf of California, 
Baja California, Mexico, February 7, 1906, by E. W. Nelson and 
E. A. Goldman ; female adult, skin and skull, no. 146783, U. S. Natl. 
Mus. (Biological Survey collection) (orig. no. 19072). 

Range. — Espiritu Santo Island, Baja California (fig. 17). Zonal 
range: Tropical. 

External characters. — Closely similar to C. leucurus extimus in 
color, but larger, and slightly darker on flanks and hind legs; tail 
about same length. 

Cranial characters. — Skull similar to that of extimus but larger 
in all dimensions except the maxillary tooth row, in which the ante- 
rior premolar {pm^) is lacking entirely in about half the specimens 
and very rudimentary in the rest. 

Color. — In worn winter pelage practically as in extimus., except 
on the flanks and hind legs, which are light pinkish cinnamon. The 
fresh pelage is not represented in the series examined. 

Measurements. — Average of 7 adults from type locality : Total length, 229 
(210-240) ; tail vertebrae, 78 (71-83) ; hind foot, 38.3 (36-40) ; ear from notch, 
9.1 (8-11). Skull: Average of 5 adults from type locality: Greatest length, 41.8 
(40.3^^2.4) ; palatilar length, 18.4 (18-19) ; zygomatic breadth, 24.2 (23.9-24.7) ; 
cranial breadth, 18.9 (18.7-19) ; interorbital breadth, 10.1 (9.8-10.6) ; postorbital 
constriction, 13.8 (13.4-14) ; length of nasals, 13.6 (12.3-14.3) ; maxillary tooth 
row, 6.5 (6.4-6.7). 

Remarks. — Although resembling the mainland race (extimus) very 
closely in color this island species has developed pronounced cranial 
and size characters. 

Specimens examined. — Total number, 14, from type locality. 

»2 Field Mus. Nat. Hist. 
»» State College, N. Mex. 



]^32 NORTH AMERICAN FAUNA [No. 56 

GITELLUS NBLSONI (Mereiam) 

San Joaquin Antelope Squirrel 

Spermophilus nelsoni Merriam, Biol. Soc. Wash. Proc. 8 : 129, Dec. 28, 1893. 
Citellus nelsoni Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 290, 1904. 
Ammospermophilus nelsoni Lyon and Osgood, U. S. Natl. Mus. Bull. 62 : 172, 1909. 
AmmospermopMlus nelsoni a,mplus Taylor, Calif. Univ. Pubs'., Zool. 17 : 15, 1916 
(20 miles south of Los Banos, Merced County, Calif.). 

r?/^e.— Collected at Tipton, Tulare County, Calif., June 24, 1893, 
by C. P. Streator • male adult, skin and skull, no. 54651, U. S. Natl. 
Mus. (Biological ourvey collection) (orig. no. 2968). 

Range. — San Joaquin Valley, Calif., from Los Banos south to Fort 
Tejon; west to the Carriso Plain and Cuyama Valley (fig. 17). 
Zonal range: Lower Sonoran. 

External characters. — Similar to G. leucurus leucurus but colors 
more buffy (less grayish) in both winter and summer pelage. 

Cranial characters. — Skull similar to those of leucurus and G. I. 
cinnamomeus.^ but larger, with heavier and more wide spreading zy- 
gomata and larger audital bullae, 

Golor. — Summer pelage; Upper parts uniform pinkish buff or pale 
pinkish buff; a narrow stripe of creamy white on either side of the 
dorsal area, from the shoulders to the rump ; fore and hind limbs light 
pinkish cinnamon, the feet pinkish buff; tail like the back for the 
basal third above^ the remainder black or fuscous black, edged with 
creamy white; tail beneath, creamy w^hite, with a subterminal band 
of blackish; under parts creamy white. Winter felage (October) : 
General tone of upper parts varying from wood brown to light drab, 
the hairs with a subterminal band of fuscous and tipped with pinkish 
buff or buffy white ; front legs light pinkish cinnamon next the body, 
shading to pinkish buff on the feet ; hind legs and thighs pinkish cin- 
namon or sayal brown. 

Molt. — The spring molt occurs in late April or early May. Speci- 
mens taken April 15 are still in worn winter pelage; a female from 
Carriso Plain, April 27, has nearly completed the molt, there being 
a patch of winter pelage still remaining on the head and another patch 
on the hinder back; another female taken at Bakersfield, May 6, 
shows new pelage coming in irregularly on the head, sides, and middle 
of the back. The fall molt occurs in September and progresses from 
the rump forward ; a specimen taken at Mendota, September 28, had 
acquired fresh winter pelage over the posterior half of the back 
and sides; another taken at Alila, October 8, has the fresh pelage 
covering all but the head and face. 

Measurements. — Average of 10 adult males from type locality : Total length, 
231.2 (218-240) ; tail vertebrae, 70 (68-79) ; hind foot, 41.2 (40-43) ; ear from 
notch (dry), 8.2 (8-9). Average of 10 adult females from type locality: Total 
length, 229.9 (221-237) ; tail vertebrae, 67.4 (62^72) ; hind foot, 39.7 (39^1) ; 
ear from notch, 8.5 (8-9.5). Skull: Average of 12 adults (3 males, 9 females) 
from type locality: Greatest length, 41.1 (40-41.9) ; palatilar length, 18.9 
(18-19) ; zygomatic breadth, 24.5 (23.5-25.7) ; cranial breadth, 19.6 (18.8-20.6) ; 
interorbital breadth, 10.1 (9.6-10.5) ; postorbital constriction, 13.8 (13.5-14.3) ; 
length of nasals, 12.4 (11.2-13) ; maxillary tooth row, 7.7 (7.2^8.5). 

Remarks. — This species is quite distinct from leucurus.^ and the 
ranges of the two do not overlap, so far as known. Its habits are 
bimilar to those of the other members of the subgenus Ammospermo- 
philus. 



1938] REVISION OF THE GROUND SQUIRRELS 183 

Comparison of a typical series of '■'■amplus'''' with typical nelsoni 
shows the differences to be too slight to warrant recognition in nomen- 
clature. The skulls average slightly larger — about one millimeter in 
iength and in zygomatic breadth. No appreciable difference in color 
can be detected. 

Specimens examined. — Total number, 210, as follows : 

California: Adobe Station (near Keru Lake), 1; Alcalde (Fresno County), 7; 
Alila (= Earlimart), 8; Bakersfield (8 miles northeast and 20 miles south), 
37 ; " Buena Vista Lake, 3 ; Carriso Plain, 11 ; Coalinga, 3 ; Cuyama Valley, 10 ; 
Dos Falos, 2; Firebaugh (Fresno County), 1 ; ** Five Willow Springs (23 
miles southeast of Simmler), 4; Huron (Fresno County), 8; Los Banos, 
30;*" Lerdo (Kern County), 2; Maricopa, 4; "' McKittrick, 5; Mendota 
(Fresno County), 7; Panoche Creek (10^15 miles southwest of Mendota), 
2;°° Panoche Pass (Fresno County), 1;"' Poso (=Famoso, Kern County), 
3; Rose Station (4 miles north of Fort Tejon), 5; ^ Santa Maria Springs (7 
miles southwest of McKittrick), 1 : Simmler (8 miles east, on Carriso Plain), 
11; Stanley (=Turk, Fresno County), 1; Sunset (= Hazelton, Kern 
County), 5; Temploa Mountains, 2; Tipton (Tulare County), 36. 

Subgenus XEROSPERMOPHILUS Merriam 

[Characters on p. 45] 

Key to Species and Subspecies 

a\ Under side of tail white mohavensis (p. 1S3) 

a'. Under side of tail not white. 
&\ Upper parts drab. 

c\ Darker tereUcaudus{^. 185) 

y. Paler (light drab) clilorus (p. 188) 

b". Upper parts vinaceous cinnamon or cinnamon drab. 

c\ Paler (light vinaceous cinnamon) tercticaudus (p. 185) 

c\ Darker (vinaceous cinnamon or cinnamon drab). 

d\ Habitat Arizona and Sonora neglectus (p. 187) 

d^. Habitat Baja California uijricus (p- 190) 

CITELLUS MOHAVENSIS (Merriam) 

Mohave Ground Squirrel 

Spermopkiliis moluivcnsis Merriam, North Amer. Fauna 2:15, Oct. 30, 1889, 
[Citcllus]mohuvvnsis Trouessart, Cat. Mamm., Sup., p. 341, 19U4. 
[Citellus] tercticaudus mohavensis Elliot, Field Columb. Mus. Pub., Zool. Ser. 3: 
291, 1904. 

Type. — Collected near Rabbit Springs, about 15 miles east of Hes- 
peria, San Bernardino County, Calif., June 29, 1886, by Frank Ste- 
phens (Grinnell and Dixon, 1918, p. 667) ; male adult, skin and skull, 
no. 186469, U. S. Natl. J\lus. (no. -ffH, Merriam collection) (orig. 
no. 315). 

Range. — Mohave Desert, Calif., west to Palmdale, Los Angeles 
County; north to Haiwee Meadows, Inyo County, south to Rabbit 
Springs, San Bernardino County (fig. 18). Zonal range: Lower 
Sonoran. 

External characters. — Similar in external appearance to C. town- 
sendii mollis but general tone of upper parts more pinkish (less gray- 
ish) without trace of mottling; imder side of tail clear whitish instead 
of cinnamon. 



»<]Mus. Vert. /ool. 

^^ W. T. Shaw collection. 

»8 Field Mus. Nat. Hist. 



184 



NORTH AMERICAN FAUNA 



[No. 56 



Cranial characters. — Skull similar to that of C. tereticaudus but 
averaging larger; slightly larger than that of O. townsendii mollis 
and differing from it in the characters distinguishing the subgenus 
Xerospermophilus ; brain case short and broad; rostrum short, the 
nasals ending nearly on a line with the premaxillae ; zygomata heavy, 
widely expanded, and twisted so that they occupy a position about 

midway between ver- 
tical and horizontal; 
postorbital processes 
broad at base, nar- 
rowing rapidly to 
slender tip, which is 
depressed ; incisors 
moderately short and 
stout, slightly re- 
curved; audital bul- 
lae broad and evenly 
rounded, consider- 
ably inflated. 

Color. — Unworn 
•winter pelage 
(March) : Upper 
parts uniform light 
drab, with a tinge of 
light vinaceous cin- 
namon, strongest on 
the forehead ; front 
feet light pinkish 
cinnamon; hind feet 
pale buff, washed 
with light pinkish 
cinnamon or pinkish 
buff; tail above fus- 
cous, overlaid with creamy white; tail beneath, clear creamy white; 
under parts creamy white. Summer pelage (May) : Upper parts 
drab or avellaneous. 

Molt. — A female specimen taken May 12 shows a new pelage cover- 
ing the head, shoulders, and most of the back. 

Measurements. — ^Average of 11 adults from Mohave Desert, Salt Wells Valley, 
and Palmdale: Total length, 222.5 (210-230) ; tail vertebrae, 65.5 (57-72) ; hind 
foot, 35.5 (32^38). Skull: Average of 11 adults from Mohave Desert, Salt Wells 
Valley, and Little Lake: Greatest length, 38.7 (38.1-40) ; zygomatic breadth, 
24.3 (23.5-25.3) ; breadth of cranium, 18.2 (17.6-19.3) ; interorbital breadth, 
8.7 (7.1-9.6); postorbital constriction, 12.7 (11.8-13.3); length of nasals, 12.9 
(12.2-13.5) ; maxillary tooth row, 7.8 (7.6-8). 

Remarks. — The Mohave ground squirrel is remarkable for the lim- 
ited extent of its range and for the fact that it has no near relatives. 
It is readily distinguished from the other unspotted ground squirrels 
by the white under surface of the tail. Its range apparently meets 
but does not overlap that of tereticaudus. The latter occupies the 
eastern side of the Mohave Desert as far west as Daggett (Elliot's 
record of C. mohavensis at Daggett (1904, p. 291) is an error, all the 
specimens taken there being C. fereticaudics) , while mohavensis occurs 
on the western side, along the Mohave River. 




Figure 18. — Distribution of Citellus mohaven»is. 



1938] REVISION OF THE GROUND SQUIRRELS 185 

Specimens examined. — Total number, 23, as follows: 

California: Haiwee Meadow (10 miles south of Owens Lake), 1; Hesperia (San 
Bernardino County), 1;"' Little Lake (Inyo County), 2;** Mohave, 1; 
Mohave Desert, 2; "Mohave River" (=Rabbit Springs, 15 miles east of 
Hesperia), 6; Oro Grande (San Bernardino County), 1; Palmdale, 1; Salt 
Wells Valley (=north end Mohave Desert), 7; Victorville, 1." 

CITELLUS TERETICAUDUS (Baied) 
[Synonymy under subspedes] 

Speciftc characters. — Similar in general external appearance to C. 
toiunsendii mollis, but never with any traces of dappling ; tail longer 
and less bushy ; ears a mere rim ; hind foot, 32-40 mm ; tail, 60-102 ; 
skull length, 34.3-39.3. Skull closely similar to that of C. mohavensis. 
Upper parts vinaceous cinnamon, pinkish cinnamon, light drab, cin- 
namon drab, or ecru drab; tail beneath, drab or buff (never white). 

CITELLUS TERETICAUDUS TERETICAUDUS (Baird) 

ROTJND-TAILED GEOUND SQITIBREL 

(Pis. 27, C; 32, C) 

Spermophilus tereticaudiis Baird, Pacific R. R. Rept. 8:315, 1857. 

Citellus tereticaudus Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 211, 1903. 

Citellus eremonomus Elliot, Field Columb. Mus. Pub., Zool. Ser. 3: 243, 1903. 

(Furnace Creek, Death Valley, Calif.) 
Citellus tereticaudus mohavensis Elliot, Ibid, p. 291, 1904 (not Spermophilus 

mohavensis Merriam). 
Citellus tereticaudus vociferans Huey, Biol. Soc. Wash. Proc. 39: 29, 1926 (San 

Felipe, Baja California). 

Ootypes. — Collected at Old Fort Yuma, Imperial County, Calif., 
by Maj. G. H. Thomas; male subadult, skin and skull, no. Hit ; 
female immature, in alcohol, no. 2490, U. S. Natl. Mus. 

Range. — Deserts of southern California and northeastern Baja 
California; north to Death Valley, Calif., and Ash Meadows, Nev.; 
east to Bunkerville, Nev., and extreme northwestern Arizona; south 
to San Felipe Bay, Baja California; west to Kramer on the Mohave 
Desert (Grinnell and Dixon, 1918, p. 669) and to La Puerta, San 
Diego County, on the Colorado Desert (fig. 19). Zonal range: Lower 
Sonoran. 

External characters. — Similar to C. toirnsendii mollis but tail much 
longer; coloration more pinkish (less grayish); under parts white 
instead of buff. Compared with C. tnohavensis : Tail longer, less 
bushy, and nearly unicolor (not white beneath). 

Cranial characters. — Skull similar to that of mohavensis^ but aver- 
aging slightly smaller. 

Color. — Cinnamon phase (unworn winter pelage) : Upper parts 
light vinaceous cinnamon, the hairs with narrow whitish bands; sides 
of nose and face washed with dull white or pale smoke gray ; eye ring 
whitish; feet white or cartridge buff; basal half of tail above^ like 
back; terminal half shaded with fuscous and edged with whitish; 
tail beneath, cartridge buff; under parts white. Drah phase: Upper 
parts drab, some individuals shaded witli cinnamon. In summer the 
pelage is thinner and slightly paler. 

"' lios Angeles Museum. 
••Mus. Vert. Zool. 
"E. T. Seton collection. 



186 



NORTH AMERICAN FAUNA 



[No. 56 



Molt. — The spring molt occurs from the middle of March to the 
middle of May, varying with the locality. There is no clear evidence 
of a fall molt, but judging from the full, silky pelage of winter 
specimens, it seems probable that there is a renewal of the pelage in 

Measurements.- — Average of 11 adults from Fort Yuma and- Pilot Knob, Calif. : 
Total length, 249.5 (235-266) ; tail vertebrae, 91.1 (81-102) ; hind foot, 36.2 
(33-38). Skull: Average of 16 adults from same region: Greatest length, 36.5 
(34.9-38.3) ; palatilar length, 16.9 (16-18.3) ; zygomatic breadth, 23 (21.8-24) ; 
breadth of cranium, 17.5 (16.8-18.5) ; interorbital breadth, 8.9 (8.2-10.3) ; 
postorbital constriction, 12.4 (11.7-13.1) ; length of nasals, 11.7 (10.3^12.8) ; 
maxillary tooth row, 7.2 (6.7-7.8). 

Remarks. — The round-tailed ground squirrel has a wide range on 
the deserts of California and Baja California, and a closely related 
form {C. t. neglectus) occupies a large part of western Arizona and 

northern S o n o r a. 
Although closeljT- re- 
lated to G. mohaven- 
sis it is quite distinct 
from that species and 
apparently their 
ranges do not over- 
lap/ Its r e s e m- 
blance in color to 
mollis does not of 
course indicate close 
relationship. 

'"''Gitellus er&mono- 
'mus^'' of Elliot was 
based on a small 
series from Death 
Valley ta,ken in late 
April. There is now 
available from this 
valley a series of 
over 30 specimens, 
representing all the 
pelage variations, 
and showing that 
there are two color 
phases with numer- 
o u s intermediate 
specimens. The cin- 
namon phase is rep- 
resented in both summer and winter pelage and shows no appreciable 
differences from typical tereticaudus from the Colorado Valley. 
The drab phase is likewise represented in both pelages. A consider- 
able series from Daggett, Calif., contains specimens representative 
of both color phases and some intermediates. 

Comparison of a series of 30 topotypes of '■''CiteTlus vociferans'^'' 
Huey with large series of typical tereticaudus shows that the alleged 

1 Elliot's assignment (1904, p. 291) of mohavensis as a subspecies of tereticaudus is 
based on a misidentification of specimens from Daggett, Calif., these being typical 
tereticaudus. 




Figure 19. — Distribution of the subspecies of Citellus tere- 
ticaudus: 1, G. t. tereticaudus ; 2, C. t. chlorus; 3, C. t. 
neglectus; 4, C. t. apricus. 



1938] REVISION OF THE GROUND SQUIRRELS 187 

characters of '"'■'vociferans''' are covered by individual and seasonal 
variation in tereticmidus. 
Specimens examined. — Total number, 231, as follows: 

Baja California: Gardner's Laguna, Salton River, 1; Mexicali, 4;* San Felipe, 

24 ; - " San Felipe Bay, 12. 

California: Amargosa Valley, 1; Bard (Imperial County), 17; =" Baregas 
Springs (=Borego, San Diego County), 1; Barstow, 2;*° Blythe Junction 
(Riverside County), 4;^ Brawley, 1; Calexico, 1; Colorado Desert (Carrizo 
Creek and Salt Creek), 5; Colorado River (opposite Parker, Ariz), 1; 
Coyote Well (Imperial County), 4;* Daggett, 34; '« Death Valley, 51;'*" 
Fort Yuma, 6; Indian Well, New River (San Diego County), 1; Ivanpah 
(San Bernardino County), 1 ; Laguna Dam (Imperial County), 4 ; La Puerta 
(San Diego County), 4 ; ^ * ^ Needles, 29; Pilot Knob (Imperial County), 6;' 
Riverside County (25 miles southwest of Ehrenburg, Ariz.), 1; Salton 
Lake, 6.* 

Nevada: Ash Meadows (Nye County), 4; Bunkerville (Clark County), 1; Las 
Vegas, 1;" Muddy River (Clark County), 2;' Pahrump Valley, 1; St. 
Thomas, 1.' 

CITELLUS TERETICAUDUS NEGLECTUS (Mereiam) 

Arizona Round-tailed Ground Squibkel 

SpermophiJus neglcctus Merriam, North Amer. Fauna 2 : 17, Oct. 30, 1889. 
Spermophilus sonorietisis Ward, Amer. Nat. 25 : 158, 1891 (Hermosillo, Sonora, 

Mexico ) . 
Anisonyx (Ictidomys) tereticaudus Allen, Amer. Mus. Nat. Hist. Bull. 7: 238, 

1895. 
[Citellus] negJectus Trouessart, Cat. Mamm., Sup., p. 341, 1904. 
Citelliis tereticandtis arizonae Grinnell, Biol. Soc. Wash. Proc, 31 : 105, 1918 

(Tempe, Ariz.). 

Type. — Collected at Dolan Spring, 12 miles northwest .of Chloride, 
Mohave County, Ariz., Februarv 9, 1889, by Vernon Bailey; male 
adult, skin and skull, no. 186470, U. S. Natl. Mus. (no. ||^, Merriam 
collection) (orig. no. 566). 

Range. — Western Arizona and western Sonora; north to Detrital 
Valley, Mohave County, Ariz.; east to Mountain Spring, Pima 
County; south to Camoa, Sonora; west to the Colorado River and 
Gulf of California (fig. 19). Zonal range: Lower Sonoran. 

External characters. — Similar to C. t. tereticaudus but darker, 
with shorter tail and hind foot. 

Cranial characters. — Skull similar to that of tereticaudus but aver- 
aging slightly larger, with narrower rostrum and interorbital region ; 
nasals longer. 

Color. — Winter pelage (February) : Upper parts cinnamon drab 
or vinaceous cinnamon, the hairs with short whitish tips; tail above, 
same color as back, tipped with fuscous and edged with buffy white; 
otherwise as in tereticaudus. Summer 'pelage: Similar to the winter 
pelage, but shorter, harsher, and averagmg more pinkish. 

Molt. — ^A specimen ( $ adult) from Fort Mohave, Ariz., March 11, 
is in a much worn pelage, with new hair covering the head; an adult 
male from Gadsden, Ariz,, April 10, shows about the same condi- 
tion; an adult female from Texas Hill, Ariz., April 24, has acquired 
a new pelage over most of the body, excepting the rump; several 

" San Diego Soc. Nat. Hist. 
' D. R. Diclcey collection. 
* MuR. Vert. Zool. 
■• Univ. Michigan Mus. Zool. 
"Field Mus. Nat. Hist. 
''California Inst. Tech. 



2gg NORTH AMERICAN FAUNA [No. 56 

specimens from Ortiz, Sonora, taken May 12, are in badly worn 
pelage, with new hair appearing on the head. 

Measurements. — Average of 10 adults (7 males, 3 females) from Dolan 
Spring, Mellen, and Fort Mohave, Ariz.: Total length, 227 (204-247); tail 
vertebrae. 72 (60-84); hind foot, 34.4 (32-37). Average of 5 adult males 
from Parker, Ariz.: Total length, 233 (225-243) ; tail vertebrae, 85.8 (77-95) ; 
hind foot, 35.5 (34.5-37). Skull: Average of 10 adults (6 males, 4 females) 
from Dolan Spring, Fort Mohave, and Mellen. Ariz. : Greatest length, 37.1 
(35.3-39.3) ; zygomatic breadth, 23.2 (22.2-23.8) ; breadth of cranium, 17.9 
(17.3-18.3) ; interorbital breadth, 8.3 (7.8-9) ; postorbital constriction, 12.3 
(12-12.7) ; length of nasals, 12.6 (11.8-13.7) ; maxillary tooth row, 7.6 (7.3-8). 

Weight. — Two specimens, taken by Vernon Bailey, near Tucson, weighed, 
respectively, 116 and 133 g. 

Remarks. — This ground squirrel, originally described as a distinct 
species, now proves to be a closely related race of tereticaudus. It 
has been redescribed twice, under the names Spennophilus sonoriensis 
and Citellus tereticaudus '•''arizonae''\ both Ward and Grinnell ap- 
parently having overlooked Merriam's description of neglectus in 
their comparisons. Large series of specimens from the type locality 
of '•'' sonoriensis^'' and from various points in central Arizona show no 
important differences from typical neglectus from northwestern Ari- 
zona. The Sonoran series apparently has slightly shorter nasals 
(average, 11.6 mm) but in the absence of any color characters, it 
seems best not to recognize this form by name. 

Specimens examined. — Total number, 292, as follows : 

Arizona: Adonde (Yuma County), 4; Ajo 1; Cibola (Yuma County), 2;* 
Colorado River, at Monument no. 204, 10; Colorado River, 5 miles north- 
east of Laguna, 3;° Congress Junction, 4; Continental (Pima County), 1; 
Coyote Mountains (Pima County), 1; Dolan Spring (Mohave County), 3; 
Dome (Yuma County), 2; Fort Lowell (near Tucson), 16;"" Fort Mohave, 
8; Gadsden, 4; Gunsight (Pima County), 1; Hackberry (Mohave County), 
1; Little Meadows (east side Black Mountains, Mohave County), 1; 
Maricopa (Pinal County), 1; Mellen (=Topock, Mohave County), 5;* 
Mineral Park (Mohave County), 1; New River (30 miles northwest of 
Phoenix), 1; Parker, 7; Phoenix, 10; Picachio Reservoir (17 miles south- 
west of Florence), 1; Quartzsite (Yuma County), 2; Quitobaquito (Pima 
Coimty), 4- Rillito (10 miles north, Pima County), 2;" Rillito Creek 
(5 miles north of Tucson), 1; Sabinos Canyon (Pima County), 3;" Santa 
Rita Range Reserve, 6; Santa Rita Mountains (west base), 1;® Tempe, 3;' 
Texas Hill (Yuma Coimty), 3; Tinajas Desert (Yuma County), 1; Tucson, 
19; Vicksburg (Yuma County), 2; Well ton (Yuma County), 5; Wickenburg, 
2; Yuma, 60. 

Sonora: Altar (20 miles north), 1;" Batamotal, 6; Camoa (Rio Mayo), 2; 
Cienega Well (30 miles south of Monument no. 204), 1; Costa Rica Ranch, 
1; Bl Doctor, 7;" Guaymas, 2;" Hermosillo, 15; Libertad (50 miles north- 
east), 2;" Obregon, 1;" Ortiz, 48; Pitiquito, 1;" Querobabi, 1;" Rancho 
Oarrizo, 2." 

CITELLUS TERETICAUDUS CHLORUS ErxiOT 

Palm Springs Ground Squirrel 

Citellus cMorus Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 242, 1903. 
Citellus tereticaudus chlorus Grinnell, Calif. Acad. Sci. Proc. (4) 3:347, 1913. 

Type. — Collected at Palm Springs, Riverside County, Calif., Febru- 
ary 16, 1903, by Edmund Heller; male adult, skin and skull, no. 
12861, Field Museum of Natural History. 

' Mus. Vert. Zool. 

8 Field Mus. Nat. Hist. 

1" D. R. Dickey collection. 

11 Univ. Michigan Mus. Zool. 

12 California Inst. Tech. 



lyss] REVISION OF THE GROUND SQUIRRELS 189 

Range. — Northwestern arm of the Colorado Desert, specifically, 
the Coachella Valley from Mecca northwest to Cabazon (Grinnell 
and Dixon, 1918, p. 674) (fig. 19). Zonal range: Lower Sonoran. 

External characters. — Similar to G . t. tereticaudus but coloration 
more drabby (less pinkish). 

Cranial charaxiters. — Practically the same as in tereticaudus. 

Color. — Winter pelage (September 27-April) : Upper parts uni- 
form light drab, sometimes with a slight tinge of pinkish cinnamon ; 
under parts white or creamy white ; sides of nose grayish white ; front 
feet buffy white; hind feet white; tail above, like back on proximal 
half, the distal half shaded with fuscous and edged with grayish 
white; tail beneath, light drab. Summer pelage: Upper parts near- 
est to ecru drab of Ridgway ; this pelage is short and much harsher 
than the winter pelage, which is soft and silky. 

Molt. — The summer pelage is acquired usually in March or April ; 
a specimen from Agua Caliente, taken April 11, 1894 is in badly 
worn condition, and shows the new pelage covering the head and 
throat, an irregular patch on the rump, and smaller patches on the 
belly ; one from Whitewater, April 21, 1894, shows new pelage cover- 
ing the entire under parts and the anterior two-thirds of the upper 
parts. A breeding female from the same locality, June 3, 1908, is in 
a moderately worn drab pelage, apparently the left-over winter 
pelage. Other specimens taken April 3 and 10 are in complete sum- 
mer pelage. The tail is renewed last ; specimens taken at Mecca, April 
24, show the new hair on the basal portion of the tail, while others 
taken at the same dates have the entire tail renewed. Winter pelage 
is apparently acquired in September ; a specimen from Palm Springs 
September 27, is in complete fresh winter pelage. 

Measurements. — Average of 10 adults (7 males, 3 females) from Palm Springs 
and Whitewater: Total length, 243.3 (232-255) ; tail vertebrae, 93.2 (84-100) ; 
hind foot, 36.4 (35-40). Ulcull: Average of 11 adults (8 males, 3 females) 
from type locality: Greatest length, 36 (35.1-37); zygomatic breadth, 22.2 
21.4-23.9) ; breadth of cranium, 17.6 (17.2-18.2) ; interorbital breadth, 8.6 
(8.1-9.5) ; postorbital constriction, 12.7 (12.2-13.3) ; length of nasals, 11.2 
(10.7-11.7) ; maxillary tooth row, 7.3 (7.2-7.6). 

Remarks. — The color characters separating this race from typical 
tereticaudus are slight, but fairly constant. Writing of this form, 
Grinnell and Dixon (1918, p. 674) say: 

The slight features by which this subspecies is distinguishable from the 
Yuma Round-tailed Ground Squirrel of the Imperial Valley southeast of Salton 
Sea may be inferred to have arisen as a result of the action of the body of 
water which formerly filled the Salton Sink to sea level in cutting off or isolat- 
ing the animals in the northwestern arm of the Colorado Desert and thus giv- 
ing them a chance to develop peculiarities of their own. 

Specimens examined. — ^Total number, 91, as follows: 

California: Agua Caliente (Riverside County), 10; Andreas Canyon, San Jacinto 
Mountains, 1; Cabazon (Riverside County), 1; Coachella (Riverside 
County), 1;" Mecca (Riverside County), 18;"'' Palm Spring.s, 38;""" 
18 17 18 Whitewater Station (Riverside County), 22."" 



"D. R. Dickey collection. 

"Mus. Vert. Zool. 

" Univ. Michigan Mus. Zool. 

'"Acad. Nat. Sci. Philadelphia. 

" Field Mus. Nat. Hist. 

^^ Los Angeles Mus. 



190 NORTH AMERICAN FAUNA [No. 56 

CITBLLUS TERETIOAUDUS APRICUS Huey 

Tkinidad Valley Geound Sqtjibeel 

Citellus tereticaudus apricus Huey, San Diego Soc. Nat. Hist. Trans. 5 : 85, 
Oct. 10, 1927. 

Type. — Collected in Valle de la Trinidad, Baja California, Mexico 
(lat. 31°20' north; long. 115°40' west), by L. M. Huey, July 13, 
1927 ; male adult, skin and skull, no. 6308, San Diego Soc. Nat. Hist. 

Range. — Known only from the type locality, Trinidad Valley, Baja 
California (fig. 19). Zonal range: Lower Sonoran. 

External characters — Similar to C. t. tereticaudus but slightly 
darker (more brownish). 

Cranial characters. — Skull similar to that of tereticaudus but 
averaging longer, with relatively longer nasals. 

Color (July specimens). — Upper parts nearly uniform cinnamon 
drab ; sides of nose and face washed with fuscous ; feet buffy white ; 
tail above, cinnamon drab at base, the distal half fuscous tipped with 
pale buff; tail beneath, pale pinkish buff; under parts white. 

Measurements. — Average of 7 adults and 3 subadults {fide Huey) : Total 
length, 244.4 (240-260); tail vertebrae, 90.3 (83-98); hind foot, 37 (35-39). 
Skull: Average of 17 adults (7 males, 10 females) : Greatest length 37.5 
(36.3-38.5) ; palatilar length, 17.2 (17-18) ; zygomatic breadth, 22.9 (21.8-23.9) ; 
cranial breadth, 17.9 (17.3-18.5) ; interorbital breadth, 8.7 (8-9.3) ; postorbital 
constriction,, 13 (11.7-13.6) ; length of nasals, 12.6 (11.9-13.2) ; maxillary tooth 
row, 7.8 (7.2-8.2). 

Remarhs. — This subspecies is a slightly differentiated form living 
in a narrow valley at the north end of the San Pedro Martir Range, 
at an elevation of about 2,500 feet, on the Pacific slope (Huey, 1. c.) ; 
the limits of its range are not known. 

Specimens examined. — Total number, 28, from type locality.^^ 

Subgenus CALLOSPERMOPHILUS Merriam 

[Characters on p. 45] 
COLOR PATTERN 

In most forms of this gToup the color pattern consists of a longi- 
tudinal white stripe on each side of the back, bordered on each side 
by a black stripe ; in some races the inner black stripes are absent or 
much reduced in extent and the outer black stripes may also be re- 
duced. Most of the races, in summer pelage, have a more or less dis- 
tinct "mantle" covering the head and shoulders, varying in color from 
cinnamon buff to tawny or russet; the median dorsal area is some 
shade of gray, buff, cinnamon, or fawn. 

PELAGE AND MOLT 

The pelage is dense and soft, the bases of the hairs plumbeous. 

Apparently there is but one molt annually, occurring usually dur- 
ing June or the first half of July, but in some cases not until the mid- 
dle of August. By the following spring, the pelage often shows a 
considerable amount of wear and the rich colors of the head and 
shoulders often have faded to a much paler shade, so that specimens 

19 Twentj'-six in collection San Diego Soc. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 191 

in this condition present a very different appearance from those in 
fresh pelage. No evidence of a molt in the fall has been discovered. 

Key to Species and Subspecies 

(Based on typical adults in summer pelage) 

o\ Median pair of dark dorsal stripes prominent. 

b\ Under side of tail paler (cinnamon buff or pinkish cinnamon). 

c\ Mantle darker and more extensive tescorum (p. 199) 

c^. Mantle paler and less extensive cinerascens (p. 198) 

b^. Under side of tail darker (tawny or russet), 
c^. Mantle darker (russet). 

(Z\ Rump darker (natal brown) trinitatis (p. 211) 

d^ Rump paler (army brown or fawn color). 
e\ Color of mantle extending to the fore back. 

f. Dorsal area smoke gray mitratus (p. 210) 

f. Dorsal area fawn color cormectens (p. 205) 

e^. Color of mantle not extending to the fore back — caslanurus (p. 201) 
(f. Mantle paler (ochraceous tawny or mikado brown). 
d\ Hind feet huffy. 

e\ Under parts huffy chrysodeirus (p. 203) 

e^. Under parts whitish bernardmvs (p. 209) 

d^. Hind feet whitish. 

e^. Tail paler beneath (tawny). 

f. Head darker (hazel) trepidus (p. 206) 

H Head paler (mikado brown) caryi (p. 197) 

e^. Tail darker beneath (russet) certus (p. 208) 

a'. Median pair of dark dorsal stripes absent or much reduced. 
6^. Tail more than 70 mm. 
c^. Size larger (hind foot, 43-40 mm) ; under parts 

darker saturatus (p. 212) 

<f. Size smaller (hind foot, 4CM4 mm) ; under parts paler. 

<f\ Upper parts paler (light pinkish cinnamon) wortmani (p. 195) 

(Z^ Upper parts darker (pinkish cinnamon or fawn). 

e\ Tail paler beneath lateralis (p. 191) 

e^. Tail darker beneath arizovensis (p. 196) 

&2. Tail less than 70 mm niadrcnsis (p. 213) 

CITELLUS LATERALIS (Say) 
[Synonymy under subspecies] 

Specific characters. — Size small to medium; hind foot, 35-46 mm; 
tail, 63-118; skull length, 39.6-45.6. Color pattern as usual in the 
subgenus (see p. 190), but coloration variable. Except for size and 
proportions, there are no characters to separate lateralis from the two 
outlying species — C. saturatvs and C. madrensis — and if the ranges 
of these adjoined the range of any of the races of lateralis^ they would 
pi'obably be found to intergrade with the latter. 

There are, however, two groups in the species lateralis., one group 
containing the subspecies lateralis., arizonensis, and tvortmani, char- 
acterized by the absence or reduced extent of the inner pair of dark 
dorsal .stripes, and the other group, comprising the remaining 11 
races, in which these stripes are prominent. 

CITELLUS LATERALIS LATERALIS (Say) 

S.\y's Mantled Ground Squirrel 

(PKs. 27, D; 32, D) 

8[ciurus'\ lateralis Say, Long's Exped. Rocky Mountains, 2: 46, 1823. 
Arctomys (Spermophilus) lateralis Richardson, Zool. Jour. 3: 519, 1828. 
Bpcrtnophilus lateralis F. Cuvier, Sup. ^ I'hist. natur. Buffon, Mamm. 1: 335, 

1831. 



192 



NORTH AMERICAN FAUNA 



[No. 56 



Tamias lateralis Allen, Boston Soc. Nat. Hist. Proc. 16: 290, 1874. 
GallospermopMlus lateralis Merriam, Wash. Acad. Sci. Proc. 3: 563, 1901. 
Citellus (Callospermophilus) lateralis Allen, Brooklyn Inst. Mus., Sci. Bull. 
1: 119, 1905. 

Type. — None designated; description apparently based on a speci- 
men taken by Long's Expedition on the Arkansas Eiver near Canon 

City,. Colo.; a speci- 
men said to be "pre- 
served in the Phila- 
delphia Museum." 
(Say, 1823, p. 47.) 

Rang e. — South- 
central Wyoming, 
central and western 
Colorado, eastern 
Utah, northern Ari- 
zona, and northern 
New Mexico; north 
to southern Fremont 
County, Wyo. (Min- 
ers Delight) ; east to 
the foothills of the 
Rocky Mountains in 
Colorado and New 
Mexico ; south to San 
Miguel County, N. 
Mex. (upper Pecos 
River) ; west to the 
Beaver Mountains, 
Utah, and the Kai- 
bab Plateau, Ariz. 
(fig. 20). Zonal 
range: Transition, 
Canadian, and Hud- 
sonian. 

External charac- 
ters. — Head and 
face mikado brown 
or pinkish cinnamon 
(paler than in G. I. 
castanurus and G. I. 
cinerascens) ; shoul- 
ders tawny; mantle 
not well defined ; 
inner pair of black 
dorsal stripes obso- 
lete or much re- 
duced ; under side of 
tail pinkish buff or 
pinkish cinnamon 
(similar to that of 
cinerascens) . 
Granial characters. — Skull about the size of that of cinerascens; 
nasals longer, extending considerably beyond the posterior border of 
the premaxillae. 




Figure 20. — Distribution of Citellus saturatus and C. mad- 
rensis and of tlie subspecies of C lateralis (subgenus Cal- 
lospermophilus) : 1, C. I. tescorum; 2, C. saturatus, 3, 
C. I. connectens; 4, C. I. ch/rysodeirus ; 5, C. I. trinitatis; 
6, C. I. mitratus; 7. G. I. trepidus; 8, C. I. cinerascens; 
9, C. I. caryi; 10, C. I. castanurus ; 11, O. I. wortmani; 
12, C. I. lateralis; 13, C. I. arizonensis ; 14, C. I. certus; 
15, C. I. bernardinus; 16, C. madrensis. 



1938] REVISION OF THE GROUND SQUIRRELS 193 

Color. — Summer pelage (Specimens from Boulder and Estes Park, 
Colo. ) : Head and face pinkish cinnamon or mikado brown ; eye ring 
buffy white; shoulders and sides of neck tawny, mikado brown, or 
cinnamon; ears pinkish cinnamon, margined with pale buff; dorsal 
area pinkish cinnamon, more or less mixed with light smoke gray 
(the gray sometimes predominating) ; rump and thighs fawn color; 
lateral stripes creamy white or pinkish buff, bordered beneath by a 
shorter black stripe; lower sides from shoulders to rump, pinkish 
buff or pale pinkish buff; feet creamy white or pinkish buff; tail 
above, fuscous black, mixed with pinkish buff or pinkish cinnamon; 
tail beneath, pinkish buff or pinkish cinnamon ; under parts creamy 
white or pale pinkish buff. Winter pelage (Specimens from Lake 
City, Colo., Sept. 17; Bridger Pass, Wyo., May 9) : Shoulders and 
sides of neck pinkish buff, more or less mixed with cinnamon and 
fuscous ; otherwise about as in summer pelage. 

Molt. — The molt takes place usually in June and July ; a male speci- 
men from Boulder, Colo, June 11, shows new pelage covering the 
head, shoulders, and most of the back and under parts, the lower 
sides, rump, and hinder back still retaining the old worn winter 
pelage; a male from Cascade, Colo., June 28, has nearly completed 
the spring molt; another male from Coulter, Colo., July 10, shows 
new pelage covering the anterior two-thirds of the body, the re- 
mainder being in badly worn winter pelage. In young individuals 
and breeding females, the molt is often delayed until August; two 
immature specimens from Estes Park, Colo., taken on July 30 and 
August 27, respectively, shoAv new pelage covering the anterior half 
of the body; an adult female from Hermit, Colo., July 31, is still in 
worn winter pelage, except for small patches of fresh hair on the 
head; another breeding female from Estes Park, August 12, shows 
a molt beginning on the head and the middle of the back. 

Measurements. — Average of 10 adnlt males from Colorado and nortberu New 
Mexico: Total length, 273 (254-292); tail vertebrae, 92 (81-107); bind foot, 
42.6 (41^4) ; ear from notcb (dry), 14.4 (14-15). Average of 10 adult females 
from same localities: Total length, 275 (252-293) ; tail vertebrae, 95.8 (83-106) ; 
bind foot, 41.5 (40-43) ; ear from notcb, 14.5 (13-16). Skull: Average of 10 
adult males from Colorado and northern New Mexico : Greatest length, 43.9 
(42.9^5.5) ; palatilar length, 20.2 (19.5-21) ; zygomatic breadth, 27.3 (26.2^ 
27.9) ; cranial breadth, 20 (19.3-20.5) ; interorbital breadth, 10.5 (10-11.1) ; 
postorbital constriction, 12.7 (12-13.4) ; length of nasals, 16.4 (15.1-17.5) ; max- 
illary tooth row, 8.6 (8.3-9.4). Average of 10 adult females from same region: 
Greatest length, 43.3 (42.1-44.4) ; palatilar length, 20.1 (19.5-20.5) ; zygomatic 
breadth, 27.3 (26.3-28.3) ; cranial breadth, 19.9 (19.3-20.3) ; interorbital breadth, 
10.2 (9.6-11.3) ; postorbital constriction. 12.7 (11.8-13.5) ; length of nasals, 
15.9 (15.2-17) ; maxillary tooth row, 8.4 (7.8-9.2). 

Weight. — Hatt (1927, p. 3) gives the average weight of 5 males as 242.4 
g (212-275) and of 5 females as 220.2 g (167-264). 

Remarks. — Say's ground squirrel, the first member of the group 
to be discovered, has a wide range in the southern Rocky Mountain 
region and westward over a large part of Utah. With the subspecies 
wortmani and arizonensis it forms a well-marked group, character- 
ized by a rather dull-colored mantle, and partial or complete sup- 
pression of the interior pair of black dorsal stripes. It differs widely 
in these characters from G. I. castanums and no intergrades between 
the two are known ; however, intergradation with C. I. caryi is clearly 
shown by a series of four specimens from Big Sandy, Wyo.; three 

154970—38 13 



j^g^ , NORTH AMERICAN FAUNA [No. 56 

of these resemble lateralis in the color of the under surface of the 
tail, but differ in having the inner pair of black stripes well-developed 
in two individuals, shorter in the other two; their skulls are large, 
agreeing with those of lateralis. Thus the two groups — lateralis and 
chrysodeirus — long supposed to be distinct, are now shown to consist 
of a single species, separable into 14 races. 
Specimens examined. — Total number, 295, as follows: 

Arizona: Kaibab National Forest, 23 (V. T. Park, 17; Jacob Lake, 4; Green- 
land Spring, 2) ; Fort Defiance (12 miles northwest, at 7,800 feet altitude), 
4; Lukachukai Mountains, 13; Tunitclia Mountains, 12. 

Colorado: Boulder, 3; Boulder County, 6; Boulder Pass, 1; Buckhorn Ranger 
Station, 2; Buena Vista, 2f California Gulch, 1; Cascade (El Paso County), 
4; Castle Rock (10 miles southwest), 4;''° Coulter, 2; Dayton (on Twin 
Lakes), 2; Douglas Spring (Routt County), 5;"^ Elk Mountains, 1; Esca- 
lante Hills (20 miles southeast of Lodore), 1; Estes Park, 18; Evergreen, 
1; Garo (Park County), 1; Gold Hill, 7; Hahns Peak (Roiitt County), 1; 
Hermit (San Juan County), 2; Idaho City (=Idaho Springs), 4; Jeffer- 
son County, 1; Lake City, 2; La Veta, 1;'" Longs Peak, 5; Manitou, 3;'° 
Marvine (Rio Blanco County), 1; Mears (Chaffee County), 1;^^ Meeker, 
1; Monshower Meadows (3 miles west of Cochetopa Pass), 1; North Park, 
2; Pagosa Springs, 3; Pearl (Jackson County), 1; Pikes Peak (10,000 
feet altitude), 1; Rabbit Ear Mountains (Grand County), 3; Rangely (Rio 
Blanco County), 1; Rifle, 1; Rio Blanco (Rio Blanco County), 2; Saguache 
Park, 1 ; Steamboat Springs (15 miles west), 1 ; Toponas, 1 f^ Ward (Boulder 
County), 1; Westclifte (Custer County), 1; White River (20 miles east of 
Rangely), 1. 

New Mexico: Baldy Mountain (Colfax County), I;'" Catskill (Colfax County), 
1; Chu.ska Mountains, 4; Cimarron (Colfax County), 2;" Costilla Pass 
(Colfax County), 2; Coyote Creek (8,400 feet altitude. Mora County), 1; 
Halls Peak (Mora County), 1; Hondo Canyon (Santa Fe County), 5; Hope- 
well (8 miles west, Rio Arriba County), 1; Jemez Mountains, 3; Long 
Canyon (3 miles north of Catskill, Colfax County), 3; Martinez (Colfax 
County), 1; Pecos (10 miles north), 1; Pecos Baldy (12,000 feet altitude), 
2; Pajado Canyon (Colfax County), 1; Red River (Taos Coimty), 1 ;^* 
Santa Fe, 1 ; Santa Fe Canyon, 2 f Taos Mountains, 1 ; Tierra Amarilla, 
1; Tres Piedras (Taos County), 13; Willis (near Cowles, San Miguel 
County), 5. 

Utah: Beaver Creek (4 miles south of Lonetree, Wyo.), 2; Beaver Mountains, 
21 (Britts Meadows, 17;^* Mount Delano, 1; Petty Mountain (15 miles 
north of Mountain Home), 1;" Puffer Lake, 2; Currant Creek, Uinta Na- 
tional Forest, 1 ; Ephraim, 4 ; Fish Lake National Forest, 3 f^ Junction of 
Green and White Rivers, 3;°^ Manila (10 miles southeast), 1;^^ Parowan 
Mountains (Brian Head), 1; Uinta Mountains, Gilbert Peak (10,000 feet 
altitude), 1; Uinta Mountains (Daggett County), 15 ; '" Vernal, 4; '=" White- 
rocks, 1. 

Wyoming: Big Sandy, 4; BridgerPass (Carbon County), 3; Islay (6 miles west, 
Laramie Coimty), 1; Laramie Mountains, 1; Maxon (Sweetwater County), 
1; Medicine Bow Mountains, 2; Miners Delight (3 miles northeast of At- 
lantic City, Fremont County), 1; Pole Mountain (15 miles southeast of 
Laramie), 3; Sherman (Albany County), 1;"" Sierra Madre Mountains 
(south base Bridger Peak), 3; South Pass City (6 miles north, Fremont 
County), 1; Springhill (12 miles north of Laramie Peak), 2; Woods P. O- 
(4 miles north of Jelm, Albany County), 5. 

2" Univ. Michigan Mus. Zool. 

-1 B. R. Warren collection. 

2= Cleveland Mus. Nat. Hist. 

23 Three in Amer. Mus. Nat. Hist., four in Mus. Vert. Zool. 

2^ Utah State Agr. CoUege. 

25 Mus. Vert. Zool. 

28 Amer. Mus. Nat. Hist. 

" Carnegie Mus. 



1938] REVISION OF THE GROUND SQUIRRELS 195 

CITELLUS LATERALIS WORTMANI (Allen) 

Wortman's Mantled Ground Sqtjirrei- 

Tamias wortmani Allen, Amer. Miis. Nat. Hist. Bull. 7 : 335. Nov. 8, 1895. 
[Sperniophilus] icortmuni Elliot, Field Columb. Mus. Pub., Zool. Ser. 2:84, 1901. 
Citellus wortmani Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 107, 1905. 
CallospennophiUis ivortmani Gary, Biol. Soc. Wash. Proc. 20: 86, 1907. 
CaUospermophilus lateralis ivortmani Gary, North Amer. Fauna 33: 84, 1911. 

Type. — Collected at Kinney Ranch, Bitter Creek, Sweetwater 
County, Wyo., July 13, 1895, by Walter W. Granger ; male adult, skin 
and skull, no. VsV/ ? Amer. Mus. Nat. Hist. 

Range. — Deserts and badlands in south-central Wyoming and 
northwestern Colorado; north to Steamboat Mountain, Sweetwater 
County, Wyo. ; south to Bear River Valley, Routt County, Colo. (fig. 
20). Zonal range: Upper Sonoran. 

External characters. — Similar to C. I. lateralis but of paler colora- 
tion. Compared with C. I. caryi: Inner pair of black dorsal stripes 
absent or very faintly indicated; colors paler, especially of the head, 
shoulders, and under side of tail. 

Cranial characters. — Skull closely similar to that of lateralis.^ but 
averaging slightly larger, except the nasals, which are shorter. 

Color. — Summer pelxige: Top of head pinkish cinnamon or vina- 
ceous cinnamon; eye ring buffy white; stripe beneath the eye reach- 
ing to the ear, sayal brown ; ears cimiamon, shading to pinkish buff 
on posterior border; shoulders and sides of neck cinnamon; sides 
of nose and lower cheeks pinkish buff; dorsal area pinkish buff or 
light pinkish cinnamon, faintly shaded with fuscous (the bases of 
the hairs fuscous) ; lateral stripes pinkish buff, bordered beneath 
with a shorter black stripe, which latter is sometimes partly ob- 
scured by cinnamon; lower sides pinkish buff; rump same color as 
the back ; thighs cinnamon buff or mikado brown ; feet pinkish buff ; 
tail above, fuscous black, mixed with pinkish buff; tail beneath, warm 
buff; under parts pinkish buff. 

Molt. — The summer molt occurs in July; an adult male taken on 
Bitter Creek, Wyo., July 7, had nearly completed the molt, new 
pelage covering the anterior portion of the body and the tail, leav- 
ing the rump with the old worn j^elage ; adult females taken July 5, 
and 9, are in badly worn winter pelage with a small patch of new 
hair appearing in the middle of the back. 

Measurements. — Average of adults (2 males, 4 females) from type locality: 
Total length, 280 (271-289) ; tail vertebrae, 95 (87-101) ; hind foot, 43.2 (41- 
44) ; ear from notch (dry), 17.1 (16-18). Sknll ; Average of (5 adults (2 males, 
4 females): Greatest length, 44.1 (43.4-46); palatilar length, 20.4 (20-21); 
zygomatic breadth. 27.0 (27.4-28.5) ; cranial breadth, 20.4 (20.2-20.7) ; inter- 
orbital breadth, 10.3 (9.0-10.0) ; postorbital constriction, 13 (12.5-13.8) ; length 
of nasals, 15.6 (15.2-16.2) ; maxiUary tooth row, 8.7 (8.3-9.1). 

Remarks. — This pale race is confined to a rather restricted area 
of desert country, and its range is almost entirely surrounded by the 
range of lateralis. 

Specimens examined . — Total num.ber, 50, as follows : 

Colorado: Snake River (5-7 miles above Lily), 5; ^ Snake River (20 miles below 

Baggs, Wyo.), 1. 
Utah: Uncorapahgre Indian Reservation, 1.^° 
Wyoming: Bitter Creek (Kinney Ranch, Sweetwater County), 42; ™ Superior, 1. 



=* E. R. Warron collection. 
^ Amer. Mus. Nat. Hist. 



IQQ NORTH AMERICAN FAUNA [No. 56 

CITELLUS LATERALIS ARIZONENSIS (Baujst) 
Aeizona Mantled Ground Sqxjierbl 

CallospermopMlus lateralis arizoncnsis Bailey, Biol. Soc. Wash. Proc. 26 : 

130, May 21, 1913. 
Citellus lateralis arizonensis Elliot, Check-list Mamm. North Amer., Sup., p. 

30, 19J7. 

Type. — Collected near Little Spring, San Francisco Mountain, 
Ariz, (altitude 8,250 feet), August 8, 1889, by C. Hart Merriam and 
Vernon Bailey; male adult, skin and skull, no. |I|^|, U. S. Natl. 
Mus (Biological Survey collection) (orig. no. 308). 

Range. — ^Mountains and high plateaus in central and eastern 
Arizona and west-central New Mexico; north to San Francisco 
Mountain, Ariz.; east and south to the Mimbres Mountains, N. 
Mex. (fig. 20). Zonal range: Transition and Canadian. 

External characters. — Similar in summer pelage to 0. I. lateralis^ 
but slightly deeper colored on head and thighs ; tail grizzled beneath 
with blackish and usually lacking a clear yellowish median area. 

Cranial characters. — Skull closely similar to that of lateralis. 

Color. — Summer pelage: Top of head and face hazel or vinaceous 
cinnamon; shoulders tawny; dorsal area mixed pinkish cinnamon 
and pale smoke gray, shading on rump and thighs to mikado brown 
or russet; light dorsal stripes from shoulders to hips, pinkish buff 
or warm buff ; outer pair of dark stripes about as broad as the light 
stripes, but shorter ; inner pair of dark stripes nearly obsolete ; sides 
of body and under parts pinkish buff or warm buff ; front feet and 
legs cinnamon or cinnamon buff, shaded with pinkish buff; hind 
feet pinkish buff, often washed with some of the russet color of 
the legs; tail above, fuscous black, mixed with ochraceous buff or 
pinkish buff; tail beneath, ochraceous buff or pale cinnamon buff, 
more or less mixed with fuscous black. Winter pelage (October 31) : 
Nose and front of face cinnamon; upper parts from crown to rump 
smoke gray, shaded with pale buff on hinder back; thighs mikado 
brown; tail above, fuscous black, mixed with pale pinkish buff; 
inner pair of black dorsal stripes present on middle of back, but 
narrower than outer pair (which are likewise short) ; light dorsal 
stripes dull creamy white; feet and under parts creamy white. 

Molt. — An adult female from San Francisco Mountain, August 13, 
is acquiring a new pelage on the head, shoulders, and middle of the 
back ; doubtless the molt begins earlier than that date in most cases, 
but with the material at hand it is not possible to determine the 
usual time. 

Measurements. — ^Average of 17 adults (10 males, 7 females) from type 
locality: Total length, 277.6 (265-292) ; tail vertebrae. 98 (90-106) ; hind foot, 
41.7 (40^4); ear from notch (dry), 14.2 (13-15.5). Skull: Average of 
10 adults (5 males, 5 females) from type locality: Greatest length, 43.8 
(42.9-^4.6) ; palatilar length, 20.1 (19.5-21) ; zygomatic breadth, 27.7 (26.8- 
28.6) ; cranial breadth, 19.8 (19.4-20.7) ; interorbital breadth, 10.6 (10.2-11.5) ; 
postorbital constriction, 13.2 (12.6-14.3) ; length of nasals, 15.9 (15.4^16.8) ; 
maxillary tooth row, 8.4 (8-8.8). 

Weight. — Hatt (1927, p. 3) gives the average weight of 8 females as 229.8 g 
(177-270) ; two males weight 200 and 220 g, respectively. 

Remarhs. — This race is a slightly marked form, occupying an 
area isolated from the typical race, lateralis.. 

Specimens examined. — Total number, 120, as follows : 



1938] REVISION OF THE GROUND SQUIRRELS 197 

Arizona: Alpine (Apache County), 4; "Apache" (=Ora Peak), 1; Baker Butte 
(Mogollon Mesa), 7; Flagstaff, 2U ; Hart Prairie (12 miles north of 
Flagstaff), 2; Little Spring (18 miles northwest of Flagstaff), 1; Monte- 
zuma Well (Yavapai County), 1; Mount Thomas, 10; Prioto Plateau 
(Greenlee County), 7; San Francisco Mountain, 46; Sprinserville, 4; White 
Mountains, 4 (Horseshoe Cienega, 3; Marsh Lake, 1) ; Williams, 1. 

New Mexico: Mimbres River (head), 1; Mimbres Mountains (Big Rocky Creek), 
1; Luna (Catron County), 1. 

CITELLUS LATERALIS CARYI (HowEix) 

Caby's Mantled Ground Squikrei, 

Callospefmophilus lateralis caryi Howell, Biol. Soc. Wash. Proc. 30: 105, May 23, 
1917. 

Type. — Collected 7 miles south of Fremont Peak, Wind River 
Mountains, Wyo. (10,400 feet altitude), July 19, 1911, by Merritt 
Gary; female adult, skin and skull, no. 176826, U. S. Natl. Mus. 
(Biological Survey collection) (orig. no. 2211), 

Range. — ^Wind Eiver Mountains, Wyo., and parts of Gros Ventre 
Range; north (apparently) to Wildcat Ridge, south of Yellowstone 
Park (fig. 20). Zonal range: Canadian and Hudsonian. 

External characters. — Similar to C . I. castanurus., but paler and 
more grayish on the back ; under side of tail paler. Compared with 
G. I. lateralis: Head and shoulders in summer pelage darker and 
more extensively tawny; inner pair of black dorsal stripes well de- 
veloped (nearly obsolete in lateralis) ; under side of tail darker 
(tawny or clay color). Compared with C. I. cinerascens : Size small- 
er; under side of tail clear tawny instead of cinnamon buff. 

Cranial characters. — Skull closely similar to that of castanurus; 
smaller than those of lateralis and cinerascens. 

Color. — Summer pelage: Top and sides of head mikado brown or 
sayal brown ; lower cheeks cinnamon buff ; eye ring white ; shoulders 
and sides of neck mikado brown; median dorsal area, from nape to 
tail, light drab, more or less shaded with pinkish cinnamon or pink- 
ish buff; lateral stripes white or creamy white, reaching from the 
ears to the rump, bordered above and below by black stripes of about 
the same width, reaching from the shoulders nearly to the hips (the 
inner pair shorter and sometimes narrower) ; lower sides pinkish 
buff; feet whitish or faintly washed with cinnamon buff; tail above, 
black, more or less mixed with cinnamon buff or cartridge buff; tail 
beneath, tawny or clay color, edged with cartridge buff or cinnamon 
buff; under parts creamy white. Winter pelage (May 16) : Head 
fawn color; sides of neck pinkish buff; back drab gray; rump and 
thighs cinnamon drab; light dorsal stripes clear white, extending 
from ears to rump; sides and under parts grayish white; otherwise 
as in summer pelage. 

Measurements. — Average of 8 adults (2 males, 6 females) : Total length, 273 
(265-282) ; tail vertel)rae, 97 (83-101) ; hind foot, 40.5 (39-42) ; ear from notch 
(dry), 13.4 (12.5-15). Skull: Average of 3 adult females: Greatest length, 42 
(41.6-42.7) ; palatilar length, 19.2 (19-19.5) ; zygomatic breadth, 25,9 (25.8-20) ; 
cranial breadth, 18.8 (18.6-18.9) ; interorbital breadth, 10 (9.7-10.4) ; postor- 
bital constriction, 12.4 (12.1-13.4) ; length of nasals, 14.4 (13.8-14.7) ; maxillary 
tooth row, 8.5 (8.4-8.7). One adult male from Kendall, Wyo.: 43.6; 20; 26.8; 
18 9 ; 9.5 ; 12.9 ; 15.5 ; 8. 

Remarks. — This race has a limited range between the ranges of 
cinerascens on the north and lateralis on the soutli. Intergradation 



198 NORTH AMERICAN FAUNA [No. 56 

with lateralis is shown by a series from Big Sanely (referred to later- 
alis) ; there is no evidence at present of intergradation with ciner- 
ascens, but doubtless this does occur ; C. I. caryi is most nearly related 
to castanurus^ with which it intergrades in the Gros Ventre 
Mountains. 

Specimens examined. — Total number, 12, as follows : 

Wyoming: Bobcat Ridge (Teton County), 2; Bull Lake (Fremont County), 1; 
Fremont Peak (5 miles south, 10,600 feet), 3; Jakeys Creek (5 miles south 
of Dubois), 3; Lake Fork (Wind River Mountains, 10,600 feet), 3. 

CITELLUS LATERALIS CINERASCENS (Merriam) 

Mebriam's Mantled Ground >Squirrex 

Tamias cinerascens Merriam, North Amer. Fauna 4 : 20, Oct. 8, 1890. 
Tamias lateralis cinerascens Tliompson [Seton], Recreation 8: 365, May 1898. 
[SpermopMlus] cinerascens Elliot, Field Columb. Mus. Pub., Zool. Ser. 2: 106, 

1901. 
Citellus cinerascens Elliot, Field Columb. Mus. Pub., Zool. Ser. 6 : 106, 1905. 
C [allospermophilus] cinerascens Warren, Mamm. Colorado, p. 168, 1910. 

Type. — Collected at Helena, Mont., August 13, 1888, by C. Hart 
Merriam; female adult, skin and skull, no. 186465, U. S. Natl. Mus. 
(fi-7T5 Merriam collection) (orig. no. 4). 

Range. — Outlying ranges in south-central Montana and north- 
western Wyoming, from Helena south to Yellowstone Park and east 
to the Beartooth Mountains (fig. 20). Zonal range: Canadian and 
Hudsonian. 

External characters. — Similar to C. I. castanurus.^ but general tone 
of upper parts more grayish (less vinaceous) ; mantle similar in 
color but sides of face and neck more ochraceous; tail much paler 
beneath (less tawny) ; hind foot longer. Compared with C. I. later- 
alis: Upper parts more grayish (less vinaceous) ; mantle darker 
(more tawny) ; median pair of black stripes always present and 
equaling the outer pair in width; under side of tail paler. Com- 
pared with C. I. tescorum: Mantle paler and less extensive; tail 
averaging longer, and paler beneath. 

Cranial characters. — Skull similar to that of lateralis in size and 
proportions, nasals shorter, reaching but little beyond posterior bor- 
der of premaxillae ; decidedly larger than the skull of castanurus or 
G . I. chrysodeirus. 

Color. — Summer pelage (topotypes, August) : Top of head, nape, 
and sides of neck below and behind the ears hazel, bordered next the 
throat with ochraceous buff or ochraceous tawny; sides of nose, 
cheeks, and eye ring pale pinkish buff; dorsal area smoke gray, 
shaded on rump and thighs with mikado brown ; lower sides pinkish 
buff ; under parts warm buff varying to pale pinkish buff ; feet pink- 
ish buff or creamy white; tail above, fuscous black, edged with cin- 
namon buff; tail beneath, pinkish buff or pale cinnamon buff, bor- 
dered on sides and tip with fuscous black, and edged with cinna- 
mon buff or buffy white. Winter pelage (adult female topotype, Au- 
gust 13) : Mantle absent; entire head, nape, back, and rump, smoke 
gray; dorsal stripes as usual, sides ivory yellow; tail much as in 
summer, but usually more mixed with blackish, and lacking the clear 
pinkish buff of the summer pelage. 



1938] REVISION OF THE GROUND SQUIRRELS IQQ 

Molt. — The molt evidently occurs in late summer, as indicated by 
the presence of adult females in winter pelage on August 13 at 
Helena; a female from Pahaska Tepee, Wyo., August 3, shows new 
summer pelage covering the head to a line a short distance back of 
the ears. 

Measurements. — Average of 4 adults (1 male, 3 females) from Yellowstone 
Park and vicinity: Total length, 286 (270-297) ; tail vertebrae, 107 (95-118) ; 
hind foot, 43.6 (41-46) ; ear from notch (dry), 14.9 (14-10). Skull: One adult 
male from Helena, Mont.: Greatest length, 45.6; palatilar length, 21; zygomatic 
breadth, 28.2 ; cranial breadth, 20.4 ; interorbital breadth, 11 ; postorbital con- 
striction, 12.7 ; length of nasals, 15.6 ; maxillary tooth row, 8.2. Average of 4 
adult females from Helena and Emigrant Gulch, Mont., and Yellowstone Park, 
Wyo.: Greatest length, 43.9 (42.0^5) ; palatilar length, 20.1 (19.3-21) ; zygo- 
matic breadth, 27.5 (26.3-29.3) ; cranial breadth, 20.1 (19.3-20.8) ; interorbital 
breadth, 105 (10.2-11) ; postorbital constriction, 13.3 (12.9-13.7) ; length of 
nasals, 14.9 (14.5-15.5); maxillary tooth row, 8.9 (8.7-9.2). 

Reinarhs. — This race is most nearly related to tescorum^ but differs 
from it in the paler color of the mantle and in the slightly longer tail, 
which is clearer yellow beneath. The series available from the type 
locality is inadec{uate to show the range of variation in summer 
pelage and the exact limits of range of the subspecies are still to be 
worked out after more thorough collecting in Montana. 

Specimens examined. — Total number 28, as follows : 

Montana: Beartooth Mountains, 2; Butte (12 miles east), 0; Deer Lodge 
County, 3;^" Emigrant Gulch (near Emigrant Peak, Park County), 1; 
Helena, 8. 

Wyoming: Pahaska Tepee (Whirlwind Peak), 3; I'ellowstone Park, 5. 

CITELLUS LATERALIS TESCORUM (Hollisteb) 

HoLLISTEIl'S IMANTLED GkOUND SQTJIRREa:. 

Citellus iCallospennophilus) ciucrascens Preble, North Amer. Fauna 27: 166, 

1908 (not of IMerriam). 
Callospennophilus lateralis tescorum Hollister, Smithsn. Misc. Collect. 50 (26) : 

2, Dec. 5, 1911. 
C Hell us lateralis tescorum Elliot, Check-list Mamm. North Amer. Sup., p. 29, 

1917. 

Type. — Collected at head of Moose Pass Branch of the Smoky 
River, All)erta (near Moose Pass, British Columbia), at 7,000 feet 
altitude, August 2, 1911, by N, Hollister; male adult, skin and skull, 
no. 1741G5, U. S. Natl. Mus.; original number, 3863. 

Range. — Northern Rocky Mountain region in western Alberta, 
eastern British Columbia, nortliern and central Idaho, and western 
Montana; north to Mount Selwyn, British Columbia; south to Edna 
and Ketclium, Idaho; west to the Columbia River Valley, southeast- 
ern British Columbia (fig. 20). Zonal range: Canadian and Hud- 
soiiian. 

Extei'nal characters. — Similar to G. I. cinerascens^ but mantle 
darker and more extensive, reaching over the shoulders and in some 
specimens nearly to the middle of the back ; under side of tail averag- 
ing darker. 

Cranial characters. — Skull closely similar to that of cinerascens; 
much larger than that of 0. I. castaiiurus. 



"" Kansas Univ. Mus. 



200 NORTH AMERICAN FAUNA [No. 56 

Color. — Head, neck, and shoulders russet, varying to mars brown; 
median dorsal area smoke gray, shaded on the rump with dull mars 
brown or Vandyke brown, this color nearly solid on the thighs; eye 
ring creamy white; light dorsal stripes creamy white, shaded with 
pale pinkish buff ; inner pair of black stripes nearly as wide as outer 
pair, but not reaching quite so far back ; sides pinkish buff or warm 
buff ; under parts pinkish buff ; front feet pinkish buff ; hind feet pale 
pinkish buff or buffy white; tail above, black, bordered with cin- 
namon buff; tail beneath, cinnamon buff or pinkish cinnamon, with 
a subterminal band of black. Winter pelage (Ptarmigan Lake, 
Alberta, July 9, and St. Mary Lake, Mont., June 5) : Head, neck, and 
median dorsal area smoke gray ; ears russet, edged with pinkish buff ; 
sides, under parts, and feet pale pinkish buff; under side of tail pink- 
ish buff or cinnamon buff. 

Variation. — While the topotype series is quite uniform in the color 
of the under surface of the tail, the series from northwestern Mon- 
tana shows more variation, some specimens having a paler tail (about 
as in cinerascens) and others a slightly darker tail, with some admix- 
ture of black. 

Molt. — A male specimen from Canadian National Park, Alberta, 
July 5, shows fresh summer pelage on the shoulders and crown ; two 
female specimens from Teton County, Mont., June 14 and 19, show 
new pelage in irregular patches on the head and shoulders; a breed- 
ing female from Thompson Falls, Mont., July 27, shows fresh pelage 
covering the head and ears, the rest of the pelage being in worn con- 
dition. A breeding female from Canadian National Park, Alberta, 
July 12, shows fresh summer pelage covering the head and part of the 
shoulders ; another fem.ale from Rocky River, Alberta, August 12, had 
just begun to molt, the new summer pelage covering only the head 
and face. 

Measurements. — Average of 16 adults from near type locality: Total length, 
292.5 (264-308) ; tail vertebrae, 103.5 (94-112) ; hind foot, 43.1 (40-46) ; ear 
from notch, 13.5 (12-15). Skull: Average of 10 adult males from near type 
locality: Greatest length, 44.1 (42.1-46.6); palatilar length, 20.6 (20-21.5); 
zygomatic breadth, 27.4 (26.2-28.9) ; cranial breadth, 19.9 (19.2-20.4) ; interor- 
bital breadth, 10.7 (9.9-12) ; postorbital constriction, 13.2 (12.5-14) ; length 
of nasals, 15.5 (14.7-16.1) ; maxillary tooth row, 8.6 (8-9.1). Average of 7 
adult females: Greatest length, 43.3 (42.3-44.6); palatilar length, 20.2 (20- 
20.5) ; zygomatic breadth, 26.9 (26.1-27.3) ; cranial breadth, 19.4 (19-19.6) ; 
interorbital breadth, 10.4 (10-10.7) ; postorbital constriction, 12.7 (12.3-13) ; 
length of nasals, 14.9 (14.3-15.9) ; maxillary tooth row, 8.4 (8.1-8.7). 

Weight. — ^A female from Lost River Mountains, Idaho, weighed 12 ounces. 

Remarks. — This wide-ranging form was for a long time confused 
with cinerascens until separated by Hollister in 1911. It is one of 
the largest and most richly colored of all the races. It undoubtedly 
intergrades vv^ith cinerascens, but there is no material available to 
prove such intergradation. It is not strongly differentiated from 
cinerascens., but may be distinguished by its darker and more exten- 
sive mantle in summer pelage, and by its darker tail. 

Specimens examined. — Total number, 279, as follows : 

Alberta: Banff, 5;''''' Burmis, 3;'' Canadian National Park, 5;'' Canmore, 3; 
Grand Cache River (60-70 miles north of Jasper House), 4; Hay River 
(near head), 1; Henry House (15 miles south), 9; Jasper House, 2; 

»>Nat. Mus. Canada. 
'^Amer. Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 201 

Jasper Park, 17 ; ^ Moose Mountain, 3 ; ^ Moose Pass, 2 ; Mountain Park, 
2 ; '^ Pobokton River, 1 ; Ptarmigan Lake, 2 ; ^ Laggan, 2 ; Rocky River 
(east branch), 3;^' Smoky River (head), 9; Southesk River, 2;^ Sulphur 
River, 2 ; Waterton Lake Park, 11.'^ 

British Coliimbia : Barkerville, 11 ; Glacier, 1 ; ^ Golden City, 1 ; " Green Moun- 
tain (near Rossland), 1 ;'^ Indian Point Lake, S ;*' Indian Point Moun- 
tain, 2;^ Jarvis Pass, 1; Jubilee Creek (head, near Barkersville), 1 ; ^^ 
Moose Pass, 6; Moose River, 4; Mount Old Glory (near Rossland), 5;*^ 
Mount Selwyn, 8; Parsnip River (head), 3; Rossland, 1;^ Sukunka River, 
5; Trail, 2;^ Wapiti River (head), 1; Yahk, 4;^ Yellowhead Lake, 1; 
Yellowhead Pass, 1. 

Idaho: Birch Creek (mountains west), 6; Bitterroot Mountains, 1;^^ Edna, 11; 
Elk Summit (Valley County), 2; Goldburg (10 miles west), 2; Ketchum, 
6 ; Lakeview, 2 ; "" Lost River IMountains, 28 ; Mullan, 16 ; Patterson, 1 : Red- 
fish Lake, 2; "Salmon River Mountains" (=Lemhi Mountains), 7; Summit 
(at Trail Creek, Blaine County), 2; Warren, 1; Wood River (head, Blaine 
County), 2. 

Montana: Bass Creek (near Stevensville), 1; Bear Creek (Great Northern 
R. R., Flathead County), 1; Florence, 4:^^ "Horse Plains" (=Plains), 10; 
Lake Como (Ravalli County), 1; Lolo Hot Springs, 1; Nyack (Flathead 
County), 2; Prospect Creek (near Thompson Falls), 3; St. Mary Lake, 3; 
Summit (Great Northern R. R., Flathead County), 1; Thompson Falls, 11; 
Thompson Pass, 2. 

CITELLUS LATERALIS CASTANURUS (Mekriam) 

Wasatoh Mantled Ground Squirrel 

Manilas castanunis Merriam, North Amer. Fauna 4 : 19, Oct. 8, 1890. 
[SpcnuopJiilns] castanurtis Elliot, Field Columb. Mus. Pub., Zool. Ser. 2: 84, 

1901. 
Citellus castanurus Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 106, 1905. 
Callospermophilus castanurus Lyon and Osgood, U. S. Natl. Mus. Bull. 62: 173, 

1909. 

Type. — Collected at Park City, Wasatch Mountains, Summit 
County, Utah, July 3, 1890, by Vernon Bailey ; female adult, skin and 
skull, no. |-|tM) U. S. Natl. Mus. (Biological SurA^ey collection) 
(orig. no. 1383), 

Range. — Mountains of extreme westei'n W^yoming, southeastern 
Idaho, and north-central Utah; north to the Teton Range, Wyo. ; 
east to the Gros Ventre and Salt River Ranges, Wyo.; south in the 
Wasatch Range to Wasatch County, Utah (and probably farther); 
west to mountains east of Inkom, Idaho (fig. 20). Zonal range: 
Canadian and Hudsonian. 

External character,^. — Compared with C. I. lateralis: Head and 
mantle darker; black dorsal stripes nuich more prominent, the inner 
pair ahvays present and e(|ual in breadth to outer pair; under side of 
tail darker (more tawny). Compared witli C. I. cinera^scc/u: General 
tone of upper parts more vinaceous (less grayish) ; sides of face and 
neck less ochraceous; tail nmch darker. Similar to C. I. connectens 
and 0. I. trepidus, but sides of face and neck darker (more broAvn- 
ish) ; tail darker beneath. 

Cranial characters. — Skull similar to that of trepidus but averag- 
ing slightly smaller, and relatively narrower across z3'gomata; de- 
cidedly smaller than that of cinerascens or of lateralis. 

31 Nat. Mus. Canada. 

^ Am<.T. Mus. Nat. Hist. 

"Mus. Vort. Zool. 

** Piovincial Mus., Victoria, Biitish Columbia. 

'^ Montana Stale College. 

^^ Carnegie Mus. 



202 NORTH AMERICAN FAUNA [No. 56 

Color. — Fresh summer pelage : Head, nape, ears, shoulders, and 
sides of neck mikado brown, shaded with cinnamon and bordered on 
the throat with cinnamon buff; median dorsal area and rump fawn 
color, sprinkled with grayish white ; light dorsal stripes pinkish buff ; 
sides light ochraceous buff ; fore feet and legs pinkish buff or cinna- 
mon buff; hind legs and thighs mikado brown, the feet pale pinkish 
buff; tail above, black, bordered with cinnamon buff; tail beneath, 
russet, the hairs edged with cinnamon buff and with a subterminal 
band of black ; under parts pinkish buff or buffy white. 

Molt. — An adult female from Park City, Utah, July 4, was ac- 
quiring fresh pelage on the head, shoulders, and middle of the back ; 
another from the Salt River Mountains, V/yo., August 21, was still 
carrying old, moderately worn pelage over most of the body except- 
ing the head, w^here new pelage is appearing. 

Measurements. — Average of 8 adult males from type locality : Total length, 
272 (25&-293) ; tail vertebrae, 97.1 (85-110) ; hind foot, 41.5 (39-44). Average 
of 10 adult females from type locality: 271 (256-280); 95.7 (91-101); 40.4 
(38.5-42) ; ear from notch (dry), 15 (14-17). Sk^iU: Average of 10 adult males 
from type locality: Greatest length, 42.3 (40.2-44.2); palatilar length, 19.8 
(19-21) ; zygomatic breadth, 26.3 (25.4-27.3) ; cranial breadth, 39.4 (18.8-20.1) ; 
interorbital breadth, 9.7 (8.9-10.2) ; postorbital constriction, 12.5 (11.8-13.1) ; 
length of nasals, 14.6 (13.5-16) ; maxillary tooth row, 8.1 (7.3-8.7). Average of 
10 adult females from type locality : Greatest length, 41.9 (40.4-42.8) ; palatilar 
length, 19.5 (18.5-20) ; zygomatic breadth, 25.8 (25.4-26.8) ; cranial breadth, 
19.1 (18.5-19.8) ; interorbital breadth, 9.8 (9-10.9) ; postorbital constriction, 
12.7 (12.1-13.7) ; length of nasals, 14.5 (13.6-15.3) ; maxillary tooth row, 7.9 
(7.1-8.4). 

Remarks. — This race clearly belongs in the chrysodeirus group, 
intergrading with subspecies trejndus in southern Idaho. A series 
of 11 specimens from Rabbit Creek, 8 miles northeast of Inkom, are 
paler than typical castanurus., although their tails are about as 
dark; one specimen from the Bannock Range, west of Swan Lake, 
has a paler tail and is best referred to trepidus. G. I. castanurus is 
widely different from lateralis and although their ranges nearly meet 
in northern Utah, no evidence of intergradation has been found. It 
iiitergrades, however, with C. I. caryi in the Gros Ventre Range and 
probably with cinet'ascens at the northern end of the Teton Range, 
Wyo. An immature specimen from Moose Creek, in that range, 
differs from typical castanurus in having the under side of the tail 
a paler shade of red, perhaps indicating an approach to cinerascens. 
Nine specimens from near the head of Twin Creek, in the Gros Ventre 
Range, Wyo., taken by Arthur B. Fuller and W. P. Bole, Jr., of the 
Cleveland Museum, are typical castanurus.^ whereas a single speci- 
men taken by H. E. Anthony, 12 miles northwest of Kendall — and 
thus in practically the same region — shows approach to caryi in its 
paler tail. 

Specimens examined. — Total number, 112, as follows : 

Idaho: Big Hole Mountains, 1; Crow Creek (Preuss Mountains), 2; Inkom (8 

miles northeast), 11. 
Utah: Barclay (Salt Lake County), 11; Blacksmiths Fork (Cache County), 

2; Bear Lake (east side), 4; Logan Canyon (Cache County), 3;" Park 

City (Summit County), 47; Sardine Canyon (Cache County), 1." 
Wyoming: Cokeville, 1; Flat Creek (at head, Teton County), 1; Gros Ventre 

Mountains (head of Twin Creek), 10;^^ Jackson, 5; Kendall (12 miles 



" Utah state Agr. College. 
« Cleveland Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 203 

northwest, Sublette County), 1; La Barge Creek (9,000 feet altitude), 2; 
Merna (Sublette County), 1; Salt River Mountains, 4; Smiths Fork 
(head, Lincoln County), 3; Stanley (=MidclIe Finey Lake), 1; Teton 
Mountains (south of Moose Creek), 1. 

CITELLUS LATERALIS CHRYSODEIRUS (Mekriam) 

Golden-mantled Gkound Squirrel 

(PL 11) 

Tamias chrysodcirus Merriam, North Amer. Fauna 4 : 10, Oct. 8, 1890. 
Callospermophilus chrysodcirus Merriam, North Amer. Fauna 16 : 90, 1899. 
iSpermophilus'\ chrysodcirus Elliot, Field Columb. Mus, Pub., Zool. Sor. 2: 84, 

1901. 
CitcUits chrysodcirus Elliot, Field Columb. Mus. Pub., Zool. Ser. 3 : 288, 19(^)4. 

Type. — Collected at Fort Klamath, Oreg., July 31, 1888, by Samuel 
Parker; male adult, skin and skull, no. 186164, U. S. Natl. Mus. (no. 
ff4t> Merriam collection) (orig. no. 143). 

Range. — Interior Oregon and eastern California north to the Co- 
lumbia River; east to the foothills of the Blue Mountains; south (in 
the Sierra Nevada) to Tulare County, Calif.; west to and including 
the Cascades in Oregon, and Mount Shasta, Calif, (fig. 20). Zonal 
range: Transition, Canadian, and Hudsonian. 

External characters. — Compared with C. saturatus and C. I. later- 
alis: Head darker; mantle more extensive and brighter colored; 
black dorsal stripes broader and more extensive, the inner pair equal 
in width to outer pair; under side of tail darker (more tawny). 
Compared with C. I. castanurus: Mantle lighter (more yellowish); 
light dorsal stripes clearer white; under side of tail paler; external 
measurements averaging smaller. 

Cranial characters. — Skull similar to that of lateralis, but smaller, 
with relatively shorter rostrum and nasals; postorbital constriction 
relatively greater. Compared with saturatus: Much smaller, but post- 
orbital constriction relatively greater. 

Color. — Summer pelage: Top of head mikado brown; sides of head 
and neck, ears, and shoulders briglit ochraceous tawny; sides of nose 
and lower cheeks warm buff; median dorsal area vinaceous buff or 
tilleul IjufF, shading to fawn color or army brown on the rump; light 
dorsal stripes creamy white or sometimes ochraceous buff; inner pair 
of black strii)es equal in length and breadth to outer pair; lower sides 
and feet pinkish buff; tail above, black, sprinkled with pinkish buff 
or ochraceous buff; tail beneath, tawny or ochraceous tawny bordered 
with black and edged with pinkish buff or ochraceous buff; under 
parts pinkish l)uff or buffy white. Winter pelage (October-April) : 
General tone of upper parts more grayish; mantle poorly defined; 
head fawn color or mikado brown; sides of head and neck cinnamon 
buff; median dorsal area liglit drab, shading to fawn color on the 
rump; under side of tail clay color; feet buffy wdiite. 

Molt. — An adult male from Beech Creek, Oreg., July 2, had nearly 
(■om])leted the molt, new |)elage covering most of the body except the 
hinder back and hind legs, which are in old, worn pelage. An adult 
female from Diamond Lake, Oreg., August 12, and another from 
Mount Shasta, Calif., August 21, had just begun to acquire new 
pelage on the head and the middle of the back. 



204 NORTH AMERICAN FAUNA [No. 56 

Measurements. — Average of 10 adult males from Fort Klamath and Crater 
Lake, Oreg. : Total length, 259 (242-275) ; tail vertebrae, 89.6 (83-94) ; hind foot. 
39.7 (39^1) ; ear from notch (dry), 15.2 (14-16). Average of 10 adult females 
from same localities: 253.5 (235-278); 88.1 (82-102) ; 39.1 (37^1) ; 15.2 (14- 
16.5). Skull: Average of 10 adult males from same localities: Greatest length, 
42.3 (41^4) ; palatilar length, 19.5 (18.5-21) ; zygomatic breadth, 26.3 (24.8-28) ; 
cranial breadth, 19.5 (19.1-20) ; interorbital breadth, 10.2 (9.3-11.2) ; postorbital 
constriction, 13.2 (12.5-13.9) ; length of nasals, 14.4 (13.3-15.8) ; maxiUary tooth 
row, 8.2 (7.6-8.6). Average of 10 adult females from same localities: Greatest 
length, 41.1 (39.6-42.7) ; palatilar length, 18.7 (18-19.5) ; zygomatic breadth, 25.5 
(23.8-26.4) ; cranial breadth, 19.3 (18.1-19.9) ; interorbital breadth, 9.5 (9.1-10) ; 
postorbital constriction, 12.7 (11.2-14) ; length of nasals, 14.4 (13.2-15.4) ; max- 
illary tooth row, 8 (7.4-8.7). 

Weight.— Average of 10 males, 181 g (155-218) ; of 10 females, 199 g (136-245) 
(Grinnell and Dixon, 1918, p. 676). 

Remarhs. — Over its very wide range, this subspecies intergrades 
with several other races. Specimens from Four Mile Lake, Oreg., a 
short distance southwest of Fort Klamath, have darker and more ex- 
tensive mantles than typical specimens ; in Siskiyou and Trinity Coun- 
ties, Calif., intergradation with the subspecies G. I. niitratus takes 
place, the large series from there being referred to the latter form. 
At the southern end of the Sierra Nevada (Sequoia National Park, 
Mount Wliitney, etc.) the animals differ from typical chin/so- 
deirus in having slightly darker mantles, thus approaching G. I. her- 
nardinus in color; their skulls are also closely similar to those of 
'bernardinus^ being longer and relatively narrower than typical 
chrysodeirus ; the tails, however, are fully as long as in chrysodeh-^s. 
Some individuals from Mount Whitney, Bishop Creek, and head of 
San Joaquin River have whitish feet and bellies, thus showing ap- 
proach to G . I. trepidns. Several specimens from East Fork of 
Kaweali River have very dark tails, darker even than those of 
G. I. certus. 

jSpeci7ne7is examined. — Total number, 543, as follows : 

California: Alta Peak (Kaweah River, Sequoia National Park), 4; Aspen 
Meadow (Tuolumne County), 7; Bald Moiuitain (8 miles west, Shasta 
County), 1; Bartle (McCloud River), 5; Bieber (Lassen County), 1; Big 
Valley Mountains, 11; Bishop Creek (9,000-10,000 feet altitude, Inyo 
County), 4; Bear Creek Valley (west of Dana, Shasta County), 1; Beswick 
(Siskiyou County), 1; Bullfrog Lake (Fresno County), 6;^^ Buck's Ranch 
(Plumas County), 1; Bunch Grass Spring (Madeline Plains), 2; Carberry 
Ranch (12 miles west of Burney, Shasta County), 6; Chaparral, 3;^ Cisco 
(Placer County), 1; Cottonwood Lakes (Inyo County), 1;^ Crown Valley 
(Middle Fork, Kings River, Fresno County), 1 ; *" Cutts Meadow (near Hunt- 
ington Lake, Fresno County ) , 2 : ^'' Dinkey Creek ( North Fork, Kings River, 
Fresno County), 1 ; Donner, 20; Eagle Lake, 1 ; Eureka Mill (Shasta County), 
1 ; Evolution Lake (head South Fork, San .Joaquin River), 1 ; *" Foster Ridge 
(near Huntington Lake, Fresno County), 1;*° Goose Lake, 2; Goose Nest 
Mountain (Siskiyou County), 6; Greenville (8 miles northwest), 13; Hay- 
den Llill (Lassen County), 3; Horse Corral Meadows (north of Mount Silli- 
man, Fresno Coimty), 4; Hope Valley (Alpine County), 1; Huntington Lake 
(Fresno County), 1;" Ice Caves (6 miles southwest of Tule Lake), 2; 
Kaweah River (East Fork, Sequoia National Park), 7; Kearsarge Pass 
(Fresno County, 5;'* Lassen County, 6; Lassen Creek (east side of Goose 
Lake), 7; Lassen Peak, 15; Letter Box (Plumas County), 2; Little Onion 
Valley, 1;^° Little Pete Meadow (Kings River, Fresno County), 1;** Long 
Valley (Mono Comity), 1;^° Madeline Divide, 1; Madeline Plains, 1; Marie 
Lake (Selden Pass, Fresno County), 1;^° Markleeville (Alpine County), 2; 



s^Miis. Vert. Zool. 
^"Cleveland Mus. Nat. Hist. 
*i Wm. T. Shaw collection. 
« Field Mus. Nat. Hist. 



1938] REVISION OF THE GIIOUND SQUIRRELS 205 

McCloud (Siskiyou County), 2; McClure Meadow (head South Fork, San 
Joaquin River), 1;*" McKinneys (Lake Tahoe), 2; Merced River (near 
head), 1; Merced River (Fish Camp, on South Fork), 1; Mohawk (Pluiuas 
County), 1; Mono Lake, 5;^" Mono Pass, 1; Mount Dana, 1; Mount Shasta, 
55 ; Mount Tallac, 5 ; Mount Unicorn, 1 ; Mount Whitney, 27 ; Mulkey Mead- 
ows (15 miles south of Mount Whitney), 5; Onion Valley (Inyo County), 
4;^* Owens River (head), 2; Petes Valley (Lassen County), 1; Picard 
(Siskiyou County), 1 ; Quincy, 1 ; San Joaquin River (near head), 1 ; Sequoia 
National Park, 4; Shingletown (Shasta County), 1; Sierra Valley (Plumas 
County), 1; Sisson (Siskiyou County), 1; Summit Meadow (Tulare County), 
1; Susan River (Lassen County), 1; Susanville (12 miles west), 2; 
Tahoe (Placer County), 1; Tenaya Lake, 1; Tuolumne Meadows, 3; Whit- 
ney Meadows (10 miles south of Mount Whitney), 1. 

Nevada: Glenbrook (Lake Tahoe), 6; Lake Tahoe, 2. 

Oregon: Antelope (Wasco County), 2; Arnold Ice Cave (Deschutes County), 
1; Austin (Grant County), 1; Beech Creek (Grant County), 1; Bend, 7; 
Chiloquin (Klamath County), 1; Crater Lake, 28; Crooked River (20 miles 
southeast of Prineville), 1; Diamond Lake (Douglas County), 5; Drew 
Creek Valley (Lake County), 2; Fort Klamath, 74; Four-mile Lake (Klam- 
ath County), 12; Francisville (Wheeler County), 1 ; Fremont (Lake County), 
4; Friend (Wasco County), 2; Gateway (Jefferson County), 2; Goose Lake 
Mountains, 1; Hay Creek (12 miles east, Jefferson County), 2; Heppner, 1; 
Howard (Crook County), 3; John Day River (Crown Rock), 3; Kamela 
(Union County), 1; Lone Rock (Gilliam County), 10; Maupiu (Wasco 
County), 2; McKenzie Bridge, 1; Meacham (Umatilla County), 1; Mill 
Creek (20 miles west of Warmsprings), G; Miller (mouth of Deschutes 
River), 6; Mount Hood, 7; Mount Mazama (Anna Creek, Crater Lake Na- 
tional Forest), 4; Naylox (Klamath Lake), 3; Ochoco National Forest 
(Crook County), 2 ; O'Leary Mountain (10 miles south of McKenzie Bridge), 
1; Paulina Lake, 4; Rock Creek (Baker County), 1; Silver Lake (10 miles 
southwest), 2; Sisters (Deschutes County), 4; Strawl)erry Mountains, 10; 
Three Sisters, 5; AVapinitia (Wasco County), 9; Warm Springs River 
(mountains north), 1; Willows (Gilliam County), 1. 

CITELLUS LATERALIS CONNECTENS (Howei.l) 
Blue Mountains Mantled Gkound Squibkei^ 

CallospermophiJuii chrysodeirus conncctcns Howell, Jour. Mammal. 12 : 1(51, 
May 14, 1931. 

Type. — Collected at Hoinestead, Oro^^., June 1, 1916, by H. H. 
Sheldon; male adult, skin and skull, no. 212461, U. S. Natl. Mus. 
(Biological Survey collection^ (orig. no. 535). 

Range. — The Blue Mountains region of nortlieastern Oregon and 
southeastern Washington (fig. 20). Zonal range: Transition and 
Canadian. 

External characters. — Similar in sunnner pelage to C. I. chryso- 
deirus^ but head and mantle darker; shoulders and fore back more 
vinaceous (less ochraceous) ; under side of tail paler. Similar in 
color to C. I. castanurus but under side of tail paler; sides of face 
and neck paler (more ochraceous). 

Cranial characters. — Skull closely similar to that of chrysodeirus^ 
averaging slightly larger. 

Color. — Summer pelage (June 1) : Head, ears, shoulders, and sides 
of neck russet, shaded on sides of neck and around ears with ochra- 
ceous buff and ochraceous tawny, and bordered next the throat with 
cinnamon buff ; nape and foreback, between shoulders, cacao brown ; 
median dorsal area fawn color, shading to army brow^n on rump and 
thighs; sides of body and feet pinkish buff; light dorsal stripes 



aoMuH. Vert. Zoo). 
"Clevelaud Mus. Nat. Hist. 



206 NORTH AMERICAN FAUNA [No. 56 

creamy white, tinged with pinkish buff; tail above, black, bordered 
with cinnamon buff; tail beneath, cinnamon or tawny, edged with 
cinnamon buff, and with a subterminal band of black; under parts 
pale pinkish buff or buffy white. Winter pelage (May 8) : Mantle 
not well defined ; top of head pinkish cinnamon ; median dorsal area 
cinnamon drab, shading to fawn color on rump and to army brown 
on thighs ; light dorsal stripes clear white, reaching to the ears ; sides 
of neck washed with cinnamon buff ; sides of body pale pinkish buff. 
Molt. — An adult female from Homestead, Oreg., June 9, and an- 
other from Paradise, Oreg., June 10, were acquiring fresh pelage on 
the head and shoulders, the pelage on the rest of the body being con- 
siderably worn and faded. 

Measurements. — Average of 7 adult males from type region : Total length, 
266 (257-280) ; tail vertebrae, 92 (80-98) ; hind foot, 41.7 (40-43) ; ear from 
notch (dry), 14.8 (14-16). Average of 9 adult females from type region: Total 
length, 266 (255-280) ; tail vertebrae, 91.5 (80-100) ; hind foot, 40.9 (40-43) ; 
ear from notch (dry), 14.1 (13.5-15). Skull: Average of 9 adult males from 
type region; Greatest length, 42.7 (41.5-44.6) ; palatilar length, 19.7 (19-20.5) ; 
zygomatic breadth, 26.5 (25.8-27.5) ; cranial breadth, 19.4 (18.5-20.3) ; interor- 
bital breadth, 9.6 (9-10.4) ; postorbital constriction, 12.3 (11-12.8) ; length of 
nasals, 14.9 (14-15.6) ; maxillary tooth row, 8.2 (7.2-8.8). Average of 8 adult 
females from type region: Greatest length, 42.4 (41.6-43.1) ; palatilar length, 
19.5 (19-20.5) ; zygomatic breadth, 26.1 (24.6-27) ; cranial breadth, 19.3 (18.8- 
19.9) ; interorbital breadth, 9.4 (8.9-9.7) ; postorbital constriction, 12.6 (11.6- 
13.4) ; length of nasals, 14.5 (13.9-15.3) ; maxillary tooth row, 8.5 (7.9-8.9). 

Bemarks. — This subspecies is most nearly related to chrysodeirus, 
with which it intergrades in the foothill region of the Blue Moun- 
tains. It is very distinct from C. I. tescorum of central Idaho, and 
their ranges apparently do not meet. 

Specimens examined. — Total number, 40, as follows : 

Oregon: Anthony (Baker County), 1 ; *^ Cornucopia (Baker County), 6 ; *^ Home- 
stead (Baker County), 7; Joseph, 1;*' Paradise (15 miles northeast, Wal- 
lowa County), 1; Troy (Wallowa County), 4; Wallowa, 1; Wallowa Can- 
yon, 2 ; Wallowa Lake, 3. 

Washington: Anatone (Asotin County), 2; Dayton, 2;^° Godman Springs (Co- 
lumbia County), 6;^^ Grand Ronde River (6 miles south of Anatone), 2; 
Humpeg Falls (Columbia County), 2.*^^* 

CITELLUS LATERALIS TREPIDUS (Taylor) 

Nevada Mantled Ground Squirrel 

Callospermopliihis trepidus Taylor, Calif. Univ. Pubs., Zool. 5: 283, Feb. 12, 1910. 
Citellus trepidus Elliot, Check-list Mamm. North Amer. Sup., p. 29, 1917. 
Callospermophilus clrrysodeirus perpallklus Grinnell, Calif. Univ. Pubs., Zool. 
17: 429, 1918 (White Mountains, Calif.). 

Type. — Collected at head of Big Creek, Pine Forest Mountains, 
Humboldt County, Nev. (8,000 feet altitude), June 27, 1909, by W. P. 
Taylor and C. H. Richardson, Jr.; male adult, skin and skull, no. 
8240, Mils. Vert. Zool. (orig. no. 768). 

Range. — Southeastern Oregon, southern Idaho, northern and cen- 
tral Nevada, and northwestern Utah; north in the Snake River Val- 
ley to southern Baker County, Oreg. (Home P. O.) ; west to Mount 
Warner, Oreg., and the Granite Range, Nev.; south to the Toyabe 
Mountains, Nev. and the AVhite and Inyo Mountains, Calif.; east to 
Bannock County, Idaho (Swan Lake) and the Snake Range, eastern 



*^ S. G. Jewett collection, Portland, Oreg. 
*^ Univ. Michigan Mus. Zool. 
■"iMus. Vert. Zool. 
*' Carnegie Mus. 



1938] REVISION OF THE GROUND SQUIRRELS 207 

Nevada (fig. 20). Zonal range: Upper Sonoran, Transition, and 
Canadian. 

External chaTacters. — Similar to G. I. chrysodei7nis^ but tail longer 
and coloration paler; upper parts more grayish (less brownish), es- 
pecially on the rump; under parts and feet more whitish (less buffy). 
Compared with C. I. castanuru^H : Upper parts paler (less brownish) ; 
mantle paler (more ochraceous) ; tail paler beneath. 

Cranial characters. — Skull closely similar to that of chrysodeirus ; 
interi^terygoid fossa and nasals averaging slightly narrower. 

Color. — Summer felage (June-July) : Top of head hazel; sides 
of head and face, and shoulders, ochraceous tawny, shaded with 
cinnamon buff; ears cinnamon buff; median dorsal area vinaceous 
fawn, more or less shaded with grayish white, becoming fawn color 
or army brown on the rump and thighs; light dorsal stripes creamy 
white or pinkish buff; both pairs of black stripes of equal width, 
reaching from shoulders to hips; lower sides pinkish buff or pale 
pinkish buff; hind feet creamy white or pale pinkish butt'; front 
feet pinkish butt'; tail above, black, mixed with warm buff and bor- 
dered with the same; tail beneath, tavrny or cinnamon, bordered 
with black and edged with warm buff; under parts creamy white, 
faintly shaded with pale pinkish buff. Winter felage (Ruby Moun- 
tains, Nev., June 20) : Median dorsal area nearly uniform pale smoke 
gray, shaded with vinaceous cinnamon on nose and head; mantle 
nearly obsolete, the shoulders and sides of neck washed with cin- 
namon butt'. 

Molt. — In two females from Wliite Pine County, Nev., June 18 and 
23, new summer pelage is coming in on the top of the head. 

Measurementfi. — Average of 10 adults (4 males, 6 females) from type locality: 
'I'otal lensth, 208.6 (2r)2-28S) ; tail vertebrae, 101.2 (90-108) ; hind foot. 40.5 
(39-44); ear from notch (dry), 13.9 (13-10). Skull: AvcniKe of 7 adults (2 
males, 5 females) from type locality: Greatest length, 42.8 (41.8-14) : palatilar 
length, 19.8 (19-20.2) ; zygomatic breadth, 26.9 (25.6-27.7) ; cranial breadth, 
19.8 (19.3-20.S) ; interorbital breadth, 9.5 (9.1-9.8) ; postorbital constriction, 
V2.2 (11.4-14) ; length of nasals, 14.9 (14.4-15.4) ; maxillary tooth row, 8.4 (8.1- 
9.3). 

Weight. — Average of 10 males from White Mountains, Calif., 182 g (166.5- 
199.5) ; of 10 females, 160 g (141-209.1) (Grinnell and Dixon, 1918, p. 682). 

Remarks. — This race is only slightly different from typical 
chrysodeirus, being chiefly distinguished by its more whitish feet 
and under parts. Occasional specimens from within the range of 
frepidus are difficult to distinguish from chrysodeirus. 

A large series of ^''perpallidus^^ (topotypes) proves on comparison to 
be practically identical w^ith trep/dic^. 

Specimens examined. — Total number, 260, as follows: 

California: Glass Mountain (Mono Hills, Mono County), 3;** Inyo Mountains, 
12; Mammoth (Mono County), 1;^ Mammoth Lakes, 1;'° Sherwin Hill, 
Round Valley (Mono County), 4;-"* White Mountains, 02.™ 

Idaho: Albion (Cassia County), 3; Bannock Mountains (8 miles west of Swan 
Lake), 1 ; Silver City, 10. 

Nevada: Arc Dome (Toyabe Mountains), 3; Badger (20 miles northwest of 
Summit Lake, Humboldt County), 2; Baker Creek (White Pine County), 
9;" Bull Run Mountaiiis, 1; Carlin, 1;^" Cottonwood Range, 3: Edgewood 
(Douglas County), 1;" Granite Creek, 5; Lehman Creek (White Pine 



4a ripvel.Tnrt I\[us. Nat. Hist. 

^8 Univ. MidiiRan Mus. Zool. 

"> Forty in Mus. Vevt. Zool. ; six in Cleveland Mus. Nat. TTist. 

" Mus. Vfirt. Zool. 

''' Amer. Mus. Nat. Hist. 



208 NORTH AMERICAN FAUNA [No. 56 

County), 1;^ Little Owyhee River, 9; Monitor Mountains (25 miles south- 
west of Eureka), 6; Mount Siegel (Douglas County), 4;°" Palisade, 1; 
Pine Forest Mountains, 37;^^ Reese River (head), 3; Ruby Mountains, 
5; Ruby Valley, 1; Stella Lake, Snake Mountains (White Pine County), 
11;^' Toyabe Mountains, 4; Virgin Valley, 1;^ Willard Creek (White Pine 
County), 5". 

Oregon: Barren Valley (Steens Mountain region), 1; Beulah, 1; Buchanan 
(Harney County), 7; Burns, 2; Cedar Mountains, -3 ; Cow Creek Lake, 1; 
Disaster Peak (Malheur Comity), 1; Drewsey (Harney County), 3; 
Harney (Harney County), 2; Home (Baker County), 2; Huntington, 5: 
McDermitt Creek (8 miles northeast of McDermitt, Nev.), 3; Mount 
Warner {— Hart Mountain, Lake County), 1; Riverside (Malheur County), 
7; Shirk (6 miles southeast of Blitzen, Harney County), 2; Steens Moun- 
tains, 2; Westfall (Malheur County), 5. 

Utah: Raft River Mountains (17 miles northwest of Kelton), 2.°* 

CITBLLUS LATERALIS CERTUS (Goldman) 

Charleston Mountains Mantled Ground Squirrel 

Callospermopliilus lateralis certus Goldman, Jour. Mammal. 2 : 232, Nov. 29, 1921. 

Type. — Collected at north base of Charleston Peak, Charleston 
Mountains, Nev., June 29, 1915, by L. J. Goldman; male adult, skin 
and skull, no. 208891, U. S. Natl Mus. (Biological Survey collection) 
(orig. no. 2270). 

Range. — Charleston Mountains, Nev. (fig. 20), Zonal range: 
Transition. 

External characters. — Similar to C . I. trepidus, but tail shorter and 
darker beneath; coloration paler and more grayish (less brownish) ; 
black dorsal stripes shorter, the inner pair narrower. Compared 
with 0. I. chrysodeirus : Coloration much paler and more grayish; 
under parts and feet white instead of buff; tail shorter and darker. 

Cranial characters. — Skull similar to that of trepidus, but averag- 
ing slightly narrower across the zygomata; nasals shorter, and 
narrower posteriorly. 

Color. — Sicmmer pelage : Head, nape, and shoulders mikado brown, 
bordered next the throat with warm buff; throat warm buff in some 
specimens; middle of back and rump smoke gray, mixed with cin- 
namon drab; light dorsal stripes white, narrowing posteriorly; dark 
dorsal stripes reduced, the outer pair scarcely reaching the hips, 
the inner pair narrovrer and still shorter; hind legs washed with 
mikado brown; hind feet creamy white or pale pinkish buff; front 
feet pinkish buff or pale pinkish buff; tail above, black, edged with 
ochraceous buff'; tail beneath, russet or tawny, bordered with black 
and edged with ochraceous buff; under parts creamy white. 'Winter 
pelage: Not seen, but a specimen in changing pelage (June 29) in- 
dicates that the head is drab gray and the mantle mostly obsolete. 

Molt. — Specimens taken at the type locality, June 29 and 30 and 
July 2 are in process of molting ; on some, the heads still retain some 
of the old winter pelage, the new hair coming in in patches ; a male 
taken July 6 has the entire mantle in summer pelage, the rest of the 
body in winter pelage. 

Measurements. — Average of 18 adults (7 males, 11 females) from type 
locality: Total length, 249 (280-258) : tail vertebrae, 77.4 (70-90) ; hind foot, 
38.5 (35-41) ; ear from notch (dry), 15.1 (14-16.5). Skull: Average of 6 males 
(adult and subadult) from type locality: Greatest length, 42.5 (41—43.4); 
palatilar length, 19.9 (19-20.5) ; zygomatic breadth, 26 (25-27.2) ; cranial 
breadth, 19.9 (19.3-20.3) ; interorbital breadth, 9.8 (9.2-10.4) ; postorbital con- 

^ Mus. Vert. Zool. 
^=Amer. Mus. Nat. Hist. 



1938] REVISION OF THE GROUND SQUIRRELS 209 

striction, 13.2 (12.S-13.8) ; length of nasals, 13.8 (13.3-14.2) ; maxillary tooth 
row, 8.1 (7.8-8.6). Average of 7 adult females; Greatest length, 41.7 (41-42.8) ; 
palatilar length, 19 (18-20) ; zygomatic breadth, 25.2 (24.4-25.7) ; cranial 
breadth, 19.5 (19-20) ; interorbital breadth, 9.4 (8.9-9.6), postorbital constric- 
tion, 12.9 (12.2-13.5) ; length of nasals, 13.7 (12.8-14.4) ; maxillary tooth row, 
8.3 (7.7-8.7). 

Remarks. — Isolated on the Charleston Mountains, this short-tailed 
pale race is nearest to treindus of the region to the northward ; al- 
though in general coloration it is among the palest of the races, its 
tail is as dark as in any of the subspecies. 

Specimens examined. — Total number, 21,°^ from type locality. 

CITELLUS LATERALIS BERNARDINUS (MEauoAM) 
San Bebnakdino Mantled Ground Squirrel 

SpermopJiiliis chrysodcirus brevicaudns Merriam, Biol. Soc. Wash. Proc. 8: 134, 

1893 (not Bpermopliilus hrcvicauda Brandt, 1884). 
Spcrmophilus (Callospennopliilus) hcrnardinus Merriam, Science (n. s.) 8: 

782, Dec. 2, 1898 (substitute for Irevicaudus) . 
Callospermophilus hernardinus Mearns, U. S. Natl. Mus. Bull. 56: 313, 1907. 
Citellus chrysodeirus 'hernardinus Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 

107, 1905. 

Type. — Collected on San Bernardino Peak, Calif., October 9, 1893, 
by J. E. McLellan; female subadult, skin and skull, no. 56661, U. S. 
Natl, Mus. (Biological Survey collection) (orig. no. 274). 

Range. — San Bernardino Mountains (6,700-11,485 feet, fide Grin- 
nell) (fig. 20). Zonal range: Canadian and Hudsonian. 

External characters. — Closely similar in summer pelage to C. I. 
clirysodevnis., but mantle averaging slightly darker, especially on the 
nape; in winter pelage upper parts more grayish (less vinaceous) ; 
under parts slightly paler (less buffy) ; tail shorter; hind foot longer. 

Cranial characters. — Skull similar to that of chrysodeirus, but 
averaging slightly larger, with longer nasals. 

Color. — Summer pelage: Top of head and face pecan brown or 
mikado brown, this color reaching on to the back between the shoul- 
ders; sides of head and neck ochraceous tawny; median dorsal area 
fawn color or smoke gray; chin and throat pale pinkish buflf; belly 
creamy white; tail beneath, tawny. Winter pelage (June) : General, 
tone grayish (decidedly different from the summer pelage) ; mantle 
only faintly indicated and much paler; top of head and face cinna- 
mon; sides of head, neck, and shoulders ochraceous buff; dorsal area 
smoke gray, shaded with cinnamon drab; sides grayish white; feet 
grayish white, faintly washed with pale pinkish buff; tail as in 
summer. 

Molt. — A male taken June 19 shows fresh summer pelage covering 
the head and neck, tlie rest of the body being in worn winter pelage ; 
a female taken June 28 shows new pelage covering the nose and face, 
reaching to the ears. 

Measurements. — Average of 7 adult males from San Bernardino Mountains : 
Total length, 255 (240-205) ; tail vertebrae, 77.3 (70-84) ; hind foot, 42 (40- 
45) ; ear from notch (dry), 15.4 (15-16). Average of 10 adult females: Total 
length, 249.5 (239-272) ; tail vertebrae, 71.1 (03-80) ; hind foot, 40.2 (.3&-42) ; 
ear from notch, 15.6 (14-16.5). Skull: Average of 9 adult males: Greatest 
length, 42.8 (41.8-43.7) ; palatilar length, 19.5 (19-20) ; zygomatic breadth, 26.0 
(26-27.8) ; cranial breadth, 19.2 (18.7-19.5) ; interorbital breadth, 10.7 (10.1- 



" Seventeen in D. R. Dickey collection. 
154970—38 14 



210 NORTH AMERICAN FAUNA [No. 56 

11.6) ; postorbital constriction, 12.9 (12.5-13.7) ; length of nasals, 15.7 (14.8- 
16.7); maxillary tooth row, 8.3 (7.9-8.8). Average of 10 adnlt females: 
Greatest length, 42 (40.4-44) ; palatilar length, 19.1 (18.5-20) ; zygomatic 
breadth, 25.8 (24.9-26.8) ; cranial breadth, 19 (18.6-19.7) ; interorbital breadth, 
10.2 (9.4-10.8) ; postorbital constriction, 12.8 (11.9-13.7) ; length of nasals, 
15.4 (14.1-16.3) ; maxillary tooth row, 8.1 (7.5-8.5). 

Remarks. — Altliough geographically isolated from chrysodeirus^ 
this race is so close to the latter in characters that a subspecific desig- 
nation seems best to express its relationship. As pointed out under 
chrysodeirus, specimens of that race from the southern Sierra Nevada 
approach herna^rdinus in certain characters. 

Specimens examined. — Total number, 49, as follows : 

California: Big Bear Lake (San Bernardino County), 1; San Bernardino 

Mountains, 48. 

CITELLUS LATERALIS MITRATUS (Howell) 

YoixA BoiXY Mantled Ground Squirrel 

(Pis., 27, A; 32, A) 

Callospermophihis chrysodeirus mitratus Howell, Jour. Mammal. 12 : 161, May 14, 
1931. 

Type. — Collected on South Yolla Bolly Mountain, Calif., July 30, 
1905, by J. F. Ferry; male adult, skin and skull, no. 138125, U. S. 
Natl. Mus. (Biological Survey collection) (orig. no. 13). 

Range. — Coast ranges of northern California, from Glenn County 
north to southern Siskiyou County (fig. 20). Zonal range: Canadian 
and Transition, 

External characters. — Similar to C. I. chrysodeirus., but upper 
parts paler and more grayish (less brownish), especially on the 
rump ; mantle darker, especially on sides of head and on shoulders ; 
tail averaging longer and darker beneath; hind feet longer. Com- 
pared with C. I. trinitatis: Upper parts much paler; mantle deeper 
colored and more extensive ; external measurements smaller. 

Cranial characters. — Skull larger than that of chrysodeiriis., with 
longer nasals. Compared with trinitatis: Skull about same length, 
but zygomata more widely expanded posteriorly and nasals longer. 

Color. — Summer pelage : Head and mantle russet, this color extend- 
ing on to the shoulders and fore back, shaded on sides with ochra- 
ceous tawny ; throat and sides of nose Avarm buff ; ears russet, shaded 
with ochraceous tawny; eye ring buffy white; median dorsal area 
smoke gray, shading in some specimens to army brown on rump and 
thighs ; light dorsal stripes creamy white ; sides of body pinkish buff ; 
feet cinnamon buff; tail above, black or fuscous black, mixed with 
warm buff; tail beneath, taAvny, bordered with fuscous black and 
edged with warm buff; under parts pinkish buff, shading to warm 
buff. Winter pelage (September 26) : Head sayal brown or mikado 
brown ; mantle nearly obsolete ; sides of neck clay color, washed with 
dull tawny; otherwise as in sununer. 

Molt. — Two adult females from Canyon Creek, Calif., taken August 
21, show new pelage coming in on the head and the middle of the 
back. 

Measurements.— ANQVBige of 10 adults (5 males, 5 females) from type locality 
(including 2 from Grindstone Creek, northern Glenn County) : Total length, 
269 (254-283) ; tail vertebrae, 94.1 (81-110) ; hind foot, 41.4 (40-43) ; ear from 
notch, 14.5 (13-10). Skull: Average of 8 adults (5 males, 3 females) from 



1938] REVISION OF THE GROUND SQUIRRELS 211 

same localities: Greatest length, 43.5 (42^44.4) ; palatilar lengtli, 20.3 (19.8- 
20.5) ; zygomatic breadth, 27.5 (26.8-28.4) ; cranial breadth, 19.9 (19.3-20.8) ; 
interorbital breadth, 10.1 (10-10.9) ; postorbital constriction, 12.7 (12.4-13.2) ; 
length of nasals, 15.7 (15.3-16.6) ; maxiUary tooth row, 8.1 (7.6-8.7). 

Remarks. — This race is most strongly developed in the vicinity of 
South Yolla Bolly Mountain. The specimens from northern Trinity 
and southern Siskiyou Counties agree in size with typical mitra- 
tus but are slightly darker; the skulls average a little longer, and 
narrower across the zygomata, thus showing approach to trinitatis. 
Specimens from Bear Creek in the northeastern corner of Trinity 
County show approach to chrysodeirus in small average size of the 
skulls. 

Specimens examined. — Total number, 83, as follows: 

California: Bear Creek (head. Trinity County), 11;" Canyon Creek (Trinity 
County), 4; Castle Lake (Siskiyou County), 2;^ Coast Range (17 miles 
west of Paskenta, Tehama County), 1; Coffee Creek (North Fork, Trinity 
County), 3;"* Grindstone Creek (Tehama County), 2; Grizzly Creek (head. 
Trinity County), 5;" Jackson Lake (Siskiyou County), 5;" Kangaroo Creek 
(Siskiyou County), 1;^ Rush Creek (head, Siskiyou County), 6;" Salmon 
Mountains (near Etna Mills), 11; Salmon River (South Fork, Siskiyou 
Mountains), 8;" Saloon Creek Divide (Si.skiyou County), 11;^* South Yolla 
Bolly Mountain, 10; Wildcat Peak (Siskiyou County), 3.=' 

CITELLUS LATERALIS TRINITATIS (Merriam) 

Trinity Mountains Mantleh) Ground Squirrel 

Callospermophiliis chrysodeirus trhiitutis Merriam, Biol. Soc. Wash. Proc. 14: 

126, July 19, 1901. 
Citellus chrysodeirus trinitatis Elliot, Field Columb. Mus. Pub., Zool. Ser. 6: 

107, 1905. 

Type. — Collected at 5,700 feet altitude in the Trinity Mountains, 
east of Hoopa Valley, Calif., September 10, 1898, by Vernon Bailey; 
female adult, skin and skidl, no. 95531, U. S. Natl. Mus. (Biological 
Survey collection) (orig. no. 6693). 

Range. — Trinity Mountains in northern Humboldt County, north 
through the Siskiyou Mountains to southwestern Oregon (fig. 20). 
Zonal range: Canadian and Transition. 

Exteimal characters. — Similar to G . I. chrysodeinis but darker and 
more brownish above, particularly on the rump; mantle averaging 
slightly darker; sides of head and neck darker; tail averaging darker 
beneath; external measurements greater. 

Cranial characters. — Skull similar to that of chrysodeirus but aver- 
aging longer and relatively narrower, the zygomata less expanded 
posteriorly. 

Color. — Summer pelage (September 10) : Top of head russet, this 
color reaching over the crown and middle of tlie nape, and on sides 
of head from the eyes to the shoulders, bordered next the throat with 
cinnamon buff or clay color; shoulders more or less shaded with 
ochraceous tawny; ears russet to ochraceous tawny; light dorsal 
stripes ochraceous buff on the shoulders, creamy wliite for the rest 
of their length, reaching to the hips but not on to the rump; median 
dorsal area fawn color, shading to natal brown on rump and thighs; 
both pairs of black stripes equal in width and nearly equal in length 
to white stripes; lower sides and under parts pinkish buff or warm 



"Mus. Vert. Zool. 



212 - NORTH AMERICAN FAUNA [No. 56 

buff; feet cinnamon buff; tail above, black mixed with ochraceous 
tawny ; tail beneath, tawny or bay edged with black and ochraceous 
tawny. 

Measurements. — Average of 6 adults (3 males, 3 females) from type locality: 
Total length, 2S1.3 (26{>-295) ; tail vertebrae, 90.7 (91-109) ; hind foot, 43.2 
(41-44) ; ear from notch, 15.2 (14.5^16.5). Skull: Average of 9 adults (5 males, 
4 females) from type locality and (3 females) from Siskiyou Mountains : Great- 
est length, 43.1 (41.2-44.8) ; paJatilar length, 19.8 (19'-21) ; zygomatic breadth, 
25.8 (24.8-27.5) ; cranial breadth, 19.4 (19.1-19.9) ; interorbital breadth, 9.9 
(8.8^11) ; postorbital constriction, 12.9 (12.2-14.4) ; length of nasals, 14.9 (14.- 
15.8) ; maxillary tooth row, 8 (7.6-8.7). 

Remarks. — This, the darkest race of the chi^ysodeims group, occu- 
pies a rather limited range in the coast mountains of northwestern 
California, intergrading with C. I. iiiitratus to the eastward. 

Specimens examined. — Total number, 30, as follows : 

California: Preston Peak, 3; Siskiyou Moimtains, 15; Trinity Mountains (east 

of Hoopa Valley), 10. 
Oregon: Briggs Creek (13 miles southwest of Galice), 1; Siskiyou, 1. 

CITELLUS SATURATUS (Rhoads) 

Cascade Mantled Ground Squirrel 

Tamias lateralis satnratus Rhoads, Acad. Nat. Sci. Phila. Proc. 1895: 43, April 9. 
[Spermophilus lateralis] satnratus Elliot, Field Colunib. Mus. Pub., Zool. Ser. 

2 : 83, 1901. 
Cltellus lateralis satnratus Elliot, Field Culumb. Mus. Pub., Zool. Ser. 6: 106, 

1905. 
C alios permophilus lateralis satnratus Miller, U. S. Natl. Mus. Bull. 79: 316, 1912. 

Type. — Collected at Lake Kichelos [=Keeclielus], Kittitas County, 
Wash. (8,000 feet altitude), September 1893, by Allan Rupert; male 
adult, skin and skull, no. 8365, Acad. Nat. Sci. Phila. (no. 1365, Ehoads 
collection). 

Range. — The Cascade Mountain region of western Washington and 
southern British Columbia; north to Tulameen, British Columbia; 
south to the Columbia River Valley, southern Washington; east to 
the Similkameen River, British Coliunbia (fig. 20). Zonal range: 
Canadian. 

External characters. — Size largest of the subgenus ; coloration very 
similar to that of C. lateralis loMralis., but slightly darker, especially 
on the head, rimip, and thighs ; mantle not Avell defined ; under parts 
more buffy (less whitish) ; median pair of dark stripes obsolete or 
much reduced and outer pair reduced in length and obscurely defined. 

Cranial characters. — Skull similar to that of lateralis but decidedly 
larger in all measurements except the nasals, which are practically 
the same length. Compared with G . I. chrysodeirus and G . I. tesco- 
rum: Size much larger with longer rostrum and nasals. 

Golor. — Fresh summer pelage: Top and sides of head russet or 
mikado brown, bordered next the throat with cinnamon buff; shoul- 
ders russet, shaded with ochraceous tawny; ears tawny, shading to 
pinkish buff on posterior margin; eye ring pinkish buff; median 
dorsal area fawn color or hair brown; hips and thighs army brown; 
light dorsal stripes dull buffy white; outer pair of dark stripes black 
or fuscous black, washed with tawny; inner pair absent or faintly 
indicated; sides Avarm buff; front feet cinnamon buff; hind feet 
pinkish buff; tail above, black, mixed with cinnamon buff; tail be- 



1938] REVISION OF THE GROUND PQUIRRELS 213 

reath, cinnamon or cinnamon buff, more or less mixed with black; 
imder parts cinnamon buff. 

Molt. — The annual molt takes place in June or July; four speci- 
mens from Trout Lake, Wash., June 27 and 28, show fresh pelage 
covering the head and shoulders, the remaining parts of the body 
being in a worn and faded pelage. 

Measurements. — Average of 10 adult males from the Cascade Moimtaius, 
Wash.: Total length, 305 (2S7-315) ; tail vertebrae, 110.9 (100-118) ; hind foot, 
46.5 (44-49) ; ear from notch (dry), 17 (1&-18). Average of 10 adult females 
from same localities: Total length, 300 (286-312); tail vertebrae, 106.5 (92- 
116); hind foot, 45.4 (43-48); ear from notch (dry), 17.8 (17-18.5). Skull: 
Average of 10 adult males from the Cascades : Greatest length, 46.4 (44-48.3) ; 
palatilar length. 21.4 (20-22.5) ; zygomatic breadth, 28.9 (27.7-30.4) ; cranial 
breadth, 20.4 (19.5-20.9) ; interorbital breadth, 11.5 (10.9-12.3) ; postorbital 
constriction, 13.4 (12.9-14.2) ; length of nasals, 16.8 (15.8-17.7) ; maxillary tooth 
row, 8.9 (8.1-9.5) ; average of 10 adult females from same localities: Greatest 
length, 45.2 (43.9-46.3) ; palatilar length, 20.8 (20-21.3) ; zygomatic breadth, 
28.1 (27.2-28.6) ; cranial breadth, 19.9 (19.5-20.2) ; interorbital breadth, 11 
(10.6-11.6) : postorbital constriction, 13.3 (12.4-14) ; length of nasals, 16 (15.6- 
16.6) ; maxillary tooth row, 9 (8.6-9.6). 

Remarks. — The Cascade mantled ground squirrel differs so mark- 
edly from the other members of the subgenus that it seems necessary 
to regard it as a full species. It resembles O. lateralis lateralis of 
Colorado more nearly than any of the other races, but is widely 
separated from it geographically. It is very different from chryso- 
deirus., whose range it nearly meets but from which it is separated 
by the Columbia River. So far as known, there is a wide gap in 
British Columbia between the range of saturatus and that of tes- 
cor^im and the two forms are very dissimilar in their characters. 

Specimens examined. — Total number, 111, as follows: 

British Columbia: Hedley, 5;" Hope-Princeton Summit, 3;" Keremeos (Ash- 
nola Creek), 2;^^ Lightning Lakes (near Boundary Momunent 77, Yale 
District), 1; Second Summit (west of Skagit River), 5;" Skagit River, 
1;'° Tulameen, 1;^ Whipsaw Creek (branch of Similkameon River), 1." 

Washington: Bald Mountain (Okanogan County), 1; Barron (Whatcom Coun- 
ty), 5; Bauerman Ridge (Okanogan County), 1; Bmnping Lake (Yakima 
County), 1; Cleveland (Klickitat County), 1; Easton, 18; (JoUleiulalo, 4; 
Hannegan Pass (Wliatcom County), 1; Hart Lake (Chelan County), 1; 
Keechelus (Kittitas County), 3; Keechelus Lake, 1; Lake Cli(>lan, 1; Ma- 
zama (Okanogan County), 1; Mount Adams, 2; Mount Aix, 1; Mount 
Rainier, 10: Mount St. Helens, 3; Rainier Fork Ridge, 4; Spray Park 
(Pierce County), 1;" Stehekin (head of Lake Chelan), 2; "Tannum River" 
(=Bumping River), 1: Trout Lake (Klickitat County), 13; Wenatcbce, 3; 
Wenatchee i[jake, 1; Whipsaw Creek (branch of Similkameen River), 1 ;'^'' 
Yakima Indian Reservation (Signal Peak), 5. 

CITELLUS MADRENSIS (Mbrriam) 

SiFRRA Madre Ma nixed Ground Squirket, 

(Pis. 27, B; Z2, B) 

Callnspermophiltis madrensis Merriam, Wash. Acad. Sci. Proc. 3 : 563, Nov. 29, 

1901. 
[Citrllus] madrensis Elliot, Field Columb. Mus. I'ub., Zool. Ser. 4: 147, 1904. 

Type. — Collected in the Sierra Madre, near Guadalupe y Calvo, 
Chiiiuahua, Mexico (7,000 feet altitude), August 27, 1898, by E. W. 



'•'' Natl. Mus. Canada. 

B» Provincial Mu.s., Victoria, British Columbia. 

*^ Univ. IMicliiKiUi Mu.s. /ool. 



214 NORTH AMERICAN FAUNA [No. 56 

Nelson and E. A. Goldman; female adult, skin and skull, no. 95363, 
U. S. Natl. Mus. (Biological Survey collection) (orig. no. 12923), 

Range. — Sierre Madre, Mexico, from northwestern Durango north 
to latitude 27°, west of Batopilas, Chihuahua; limits of range not 
known (fig. 20). Zonal range: Transition. 

External characters. — Similar to C . lateralis lateralis and G. I. 
arizonensis., but smaller, with much shorter tail ; colors much duller, 
with scarcely any trace of a mantle; black stripes short and poorly 
defined, tending to become obsolete ; white stripes reaching nearly to 
the root of the tail. 

Cranial characters. — Skull similar to that of lateralis but smaller 
and relatively narrower; zygomata more appressed; brain case nar- 
rower and more highly arched. 

Color. — Worn simimer pelage (August 26-September 3) ; Head 
and face hazel or sayal brown; eye ring buffy white; lower cheeks, 
sides of lips, and fore legs warm buff ; sides of neck and shoulders 
rather faintly washed with cinnamon buff and ochraceous tawny; 
ears thinly clothed on outer surface with cinnamon hairs; general 
tone of upper parts cinnamon drab or fawn color, darkest and purest 
on rump and thighs; light dorsal stripes dull whitish or pinkish 
buff; dark stripes blackish, often very faintly indicated; sides of 
body cinnamon buff or buffy white ; tail above, fuscous black, mixed 
with warm buff ; tail beneath, warm buff, tipped with blackish ; hind 
feet pinkish buff; under parts pinkish buff or buffy white. 

Measurements. — Average of 10 adults (3 males, 7 females) from type local- 
ity: Total length, 227.8 (215-243) ; tail vertebrae, 58.8 (52-66) ; hind foot, 38.7 
(37-40) ; ear from notch (dry), 16.4 (15-18). ^kull: Average of 7 adults (2 
males, 5 females) : Greatest length, 42.3 (41.1-44.1) ; palatilar length, 20.1 
(19.5-20.5) ; zygomatic breadth, 25.6 (24.8-26.5) ; cranial breadth, 18.9 (18.5- 
19.3) ; interorbital breadth, 10.2 (9.9-10.5) ; postorbital constriction, 12.3 (11.9- 
12.7) ; length of nasals, 15.8 (15.1-17) ; maxillary tooth row, 8.5 (8.3-8.7). 

Remarhs. — The Sierra Madre ground squirrel, although clearly 
derived from the C. I. lateralis stock, has become so strongly differ- 
entiated that it must be treated as a distinct species. The known 
range of tnadrensis is separated from that of arizonensis by a gap of 
about 500 miles, though further collecting in the Sierra Madre may 
somewhat extend the range of the present form northward. 

E. W. Nelson, who discovered the species, writes of its habits at 
the type locality as follows : 

Very abundant in the pine woods about the base of Mohinora and reaches 
the extreme summit of the moimtains. We saw them all along our route from 
above Guanacevi In Durango to Guadalupe y Calvo. Their range extends 
only a little below 7,000 feet and does not enter the pinyou belt. 

Specimens examined. — Total number, 21, from type locality. 

FOSSIL SPECIES 

Eight fossil forms in the genus Citellus have been described from 
North America. Of these, two are from Miocene formations, two 
from the Pliocene, and four from the Pleistocene. 

The most primitive species at present known is Citellus {Protosper- 
mophilus) quatalensis Gazin (1930, p. 64), from Quatal Canyon, 8 



1938] REVISION OF THE GROUND SQUIRRELS 215 

miles east of Cuyama Valley, Calif. Of this Miocene form the de- 
scriber says : 

On the basis of available material, Citellus (Protospcnuophilus) quatalcnsis 
appears to resemble the Recent genus or subgenus OtospermopMlus more nearly 
than it does any of the other sciurids. Moreover, the new form presents an 
association of primitive characters which suggests that the dentition possessed 
by the modern otospermophilids is more primitive than that exhibited by the 
typical citellids. This is also indicated by the development of the premolars, 
which in the case of typical CiteUiis appear to have taken on more completely 
the characters of the molar teeth. From this consideration it seems probable 
that species of Citellus may have been derived from an Otospermophilus-like 
ancestor, probably later than the stage represented by C. (P.) quatalensis, 
assuming this form to be in or near the line of descent of the ground squirrels. 

Citellus 7'idgirayi Gazin (1932, p. 61), from the Skiill Spring 
Miocene beds, Malheur County, Oreg., is about the size of Citellus 
{Callosper?nophilus) chrysodeirus and resembles that species perhaps 
as nearly as it does any living form. It, shows conspicuous differ- 
ences, however, and cannot with certainty be assigned to any of the 
modern subgenera. Compared with CaUosiyermophilus the skull of 
C. ridgwayi is flatter on the superior surface and wider between the 
orbits. "The outer and anterior margin of the zygoma . . . con- 
tinues forward on the side of the muzzle as a small ridge, following 
the contour of the incisor to the alveolus" (Gazin). The molars are 
low-crowned, as in CallospermopMlus ; ;;»*, 7;i\ and w- are broader 
than long, and differ from the teeth of CallospermopMlus in having 
a much less prominent i^arastyle. On m ^ and m - the protoloph and 
metaloph are not parallel as in C alios permophiluJi^ but converge 
toward the inner side as they join the protocone. ]\P has a reduced 
parastyle, a prominent protoloph, and a slight ridge in the basin of 
the tooth running toward the metacone. 

OtospermopMlus gidleyl Morriam, Stock, and INIoody (1925, p. 68), 
from the Kattlcsnake Pliocene, John Day Valley, Oreg., is thus char- 
acterized by the descri))prs: 

It is clearly distinguished from the other sciurids by the combined char- 
acters of the relatively shorter anteroposterior extent of all the cheek 
teeth. ... A charnctcr which seems to distinguish the fossil distinctly from 
the living species of the citellid group is the much greater relative depth aud 
apparently shorter proportions of the lower jaw. 

Citellus hensoni Gidley (1922, p. 122), from the San Pedro Valley, 
Ariz. (Pliocene), was described from the molars only; as stated by 
Gidley, these teeth seem most nearly like those of OtospermopMlus ; 
the u])per molars are relatively narrow in the transverse diameter, 
and the posterior loph is "broken up into two distinct but slightly 
joined cuspules, the inner one of which is a rounded cone entirely 
disconnected from the protocone." 

Citellus tuitus Hay (1921, p. 627), from Val Verde Mine, Ariz. 
(Pleistocene), Avas compared by the describer with C, franJdinii, but 
it seems to be nearer to C. mexicanus ; the tooth rows converge pos- 
teriorly about as in that species; the molars are higher-crowned on 
the inner side; mi' is longer llian broad (nearly quadrate in mexi- 
ca.'ims). Except for the more hypsodont molars, (his species might 
be referred to the subgenus Ictidomys. 

Citellus coeMj<ei Gidley (1922, p. 121), from the San Pedro Valley, 
Ariz. (Pleistocene), was based on a right maxillary wnth all the 
molars, and part of a lower jaAv. Both this species and C. tuitus 



216 NORTH AMERICAN FAUNA [No. 56 

seem to be more closely related to C . mexicamus than to any other 
living species ; both differ from mexicanus in having somewhat stouter 
and broader molars. The present species may with little hesitation 
be referred to the subgenus Ictidomys. Compared with tuitus, it 
differs in having the protocone of the upper molars stouter and less 
hypsodont; the metaloph on m^ and m- is separated from the pro- 
tocone by a wide sulcus; on m^ the protoloph is likewise separated 
from the protocone by a wide sulcus ; m^ and m^ are somewhat heavier 
than in tuitus but m^ is relatively shorter. 

Citellus taylori Hay (1921, p. 616), based on a lower jaw from 
Pleistocene deposits near San Diego, Tex., is described as follows : 

The jaw and teeth seem to resemble most those of Citellus toivnsendi i=^wash- 
ingtoni]. . . . The molar teeth have the same short, broad form, and the jaw 
itself is hardly different. The anterior crest of each tooth is, however, not so 
high as in that species and not so abruptly steep on its hinder face. . . . 
The premolar as long as wide ; the cusps of its anterior crest with a shallow 
notch between them. 

Citellus heecheyi captus Kellogg (1912, p. 164) from Pleistocene 
deposits at Rancho La Brea, Calif., is characterized by the describer 
as follows: 

In the skull the width between the premaxillae and the anterior width of 
palate are less than in Citellus b. fisheri. The bullae are relatively long and 
narrow. In the lower jaw, the tooth row is long and the teeth heavy in pro- 
portion to the size of the ramus ; the coronoid process, angle, and condyle are 
small. 

This form is considered by Dice (1925, p. 125) to be referable to 
O. beecheyi fisheri. 

In addition to the above species, several of the modern species 
have been found in Pleistocene deposits, as follows : 

Citellus tridecetnlineatus has been recorded from the Conard 
Fissure, Newton County, Ark. (Brown, 1908, p. 194) ; C. douglasii 
and C. {CalJospermoj^hilus) chinjsodeirus have been found in cave 
deposits in Shasta County, Calif. (Kellogg, L., 1912, p. 155). 



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BuRD, John S., and Stewart, G. R. 

1918. A STUDY OF FUMIGATION METHODS FOR KHXING GROUND SQUIRRELS. 

Calif. State Comn. Hort. Monthly Bull. 7: 762-764. 
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1914. THE STRIPED GROUND SQUIRRELS OF COLORADO. Colo. Off. State Ent. Cir. 

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1916. THE WYOMING GROUND SQUIRREL IN COLORADO WITH SUGGESTIONS FOR 

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1918. RODENTS OF COLORADO IN THEIR ECONOMIC RELATION. Colo. Off. State 

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1920. A CONTRIBUTION TO THE LIFE HISTORY OF THEl WYOMING GROUND SQUIRREL 

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1938] REVISION OF THE GROUND SQUIRRELS 219 

BuET, William Heney. 

1936. NOTES ON THE HABITS OF THE MOHAVE 6EOUND SQUIREEL. Jour. Mammal. 

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1907. A coloeado eecoed foe callospermophilus woetmani, with notes on 
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1911. A BIOLOGICAL stiRVErr OF COLOEADO. Noi'th Amer. Fauna 33, 256 pp., illus. 
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1918. the work OF THE EODENT coNTBOL DIVISION. Calif. State ComiL Hort. 
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1925. RODENTS AND LAGOMORPHS OP THEI EANCHO LA BREA DEPOSITS. Carnegie 

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1934. A SYSTEMATIC STUDY OF A COLLECTION OF JfAMMAI.S FROM SOUTHE^SN 

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1830. sketch op A JOUENEY TO THE ROCKY MOUNTAINS AND TO THE COLUMBIA 

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1937. HIBERNATING GROUND SQUIRREL. Nat. Hist. 39 : 214-215, illus. 
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1936. AN ALBINO GEOUND SQUIREEL. Nat. Mag. 28: 338, 1936. 
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1931. seasonal activity and geowth in the douglas geound squierel. 
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1934. BURROWS AND UUEEOWING HABITS OP THE DOUGLAS GROUND SQUIRREL. 

Jour. Mammal. 15: 189-193, illus. 

1935a. VARIATION OP the DOUGLAS GROUND SQUIRREL IN DIFFERENT PARTS OF ITS 

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1935b. A STUDY OF the EELATION of the DOUGLAS GEOUND SQUIRREL TO THE 
VEGETATION AND OTHEK ECOLOGICAL FACTORS IN WESTERN OEEGON. 

Amer. Midland Nat. 10 : 949-959, illus. 
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1903. descriptions of twenty-seven appaeently new species and subspecies 

of MAMMALS. Field Columb. Mus. [Chicago] Pub., Zool. Ser. 3:. 
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1904. CATALOGUE OP MAMMALS COLLECTEDi BY E. HETJ.KE IN SOUTHERN CALIFOR- 

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1777. SYSTEM A REGNI ANIMALIS, V. 1. 636 pp. 

FiTZPATRicK, Frederick L. 

1925. THE ECOLOGY AND ECONOMIC STATUS OF OTEUXUS TRIDECEMLINBATUS. 

Iowa Univ. Studies Nat. Hist. 11 : 1^0, illus. 
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1934. THE REPRODUCTIVE CYCLE IN THE FICMALE GEOUND SQUIRREL, CITELLUS 

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1922. the occurren-ce of tularaemia in nature as a dise.vse of man. u. s. 
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1937. SOURCES OF INFECTION AND SEASONAL INCIDENCE OF TULARAEMIA IN MAN. 

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1929. DEVELOPMENT OP cAPTTVT': SQUIRRELS. Jour. Mammal. 10: 315-317. 
Garlough, Francis Earl. 

1918. eodent ee-\dicat10n work op the biotxx3ical survey in california. 

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1930. A TEETIARY VEETEHRATE fauna FBOM the UPPEK CUYAMA drainage BASIN, 

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1932. A mioci':ne mammalian fauna from souiheastekn orbgon. Carnegie 
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220 NORTH AMERICAN FAUNA [No. 56 

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1933. habits of the ground squikeel citelltjs lyratus on st. lawrence 

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Gbsnee, Konrad. 

1551. HISTOEIAE3 ANiMALiTjM, V. 1. De Quadrupedibus viviparis. 1104 pp. 
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1922. preliminary report on fossil VERTEBEiVTES OF THE SAN PEDRO VALLEY, 
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MORPHA. U. S. Geol. Survey, Prof. Paper 131-E, pp. 119-131. 
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1889. FOOD HABITS OF THE STRIPED PRAIRIE-SQUIREBL ( SPEEMOPHILUS 13- 

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1934. NOTES on an apparent defense ATTITUDE IN GROUND SQUIRRELS. JOUT. 

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1921. TWO new RODENTS FROM OREGON AND NEVADA. Jour. Mammal. 2: 232- 
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1929. A NEW ANTELOPE SQUIRREL FROM ARIZONA. Jour. Wasli. Acad. Sci. 19: 

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1933. the striped spbemophile in fairfield county, OHIO. Jour. Mammal. 
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1925. notes on some mammals of mO'NTmoebncy county, MICHIGAN. Jour. 
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1932. the franklin spermophilb in Ontario. Jour. Mammal. 13: 277. 
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1918a. six new mammals from the mohave desert and inyo regions of Cali- 
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1933. REVIEW OF the recent mammal fauna of CALIFORNIA, Calif. Univ. 

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1918. NATURAL HISTORY OF THE GKOUND SQUIRRELS OF CALIFORNIA. Calif. State 

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1930. VEKTEBEA,TB NATURAL HISTORY OF A SECTION OF NORTHERN CALIFORNIA 

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1924. animal life in the yosemite. 752 pp., illus. Berkeley, Calif. 
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1914. THE hibernation of certain animals. Pop. Sc-i. Monthly 84: 147- 
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1926. changes during growth in the skull of the rodent otospermophh-us 
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1931. TREB-CLiMBiNG CAiiosPERMOPHiLus. Murrelet 12: 54. 
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1932. NEW mammals from ST. LAWRENCE ISLAND, BEliING SEA, ALASKA). Calif. 

Univ. Pubs., Zool. 38: 391-404, illus. 
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1926. A NEW dorsal gland in the GROUND SQUIRRIEI>, OALLOSPERMOPHILUS, 

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1927. NOTES ON THE GROUND SQUIRREL, CALLOSPERMOPHILUS. Mich. Univ., MuS. 

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1921. descriptions of species op pleistocene VEETEBEATA, types or SPECIMENS 
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MUSEUM. U. S. Natl. Mus. Proc. 59: 599-642, illus. 
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3911. the MAMMALS OF EITTBRROOT VALLEY, MONTANA, IN THEIR, RELATION TO 

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1938] REVISION OF THE GROUND SQUIRRELS 221 

HisAW, Fkedeeick L., and Emeby, Fuedeeick E. 

1927. FOOD SELECTION OF GEOUND SQUIKKELS, CITEIXUS TKlDEJCEMLINEiATUS. 

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HoixiSTER, Ned. 

1911. FOTJK NEW MAMMALS FROM THE CANADIAN ROCKIES. SmitllSll. MiSC. Col- 
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1841. the botany of captain beechey"s voyage ... to the pacific and 

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1924. the mammals of mammoth, mono county, California. Jour. Mam- 

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1917. description of a new race of say's ground squirrel from WYOMING. 

Biol. Soc. Wash. Proc. 30 : 105-106. 

1928. descriptions of six new north American ground squireels. Biol. 

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1931. PREI.IMINARY DESCRIPTIONS OF FOUR NEW NORTH AMERICAN GROUND 

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1926. a new race of CITEXLUS nERETnCAUDUS FROM LOWI21 CALIFORNIA. Biol. 

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1927'. A NEW LOUISIANA HERON AND A NEW ROUND-TAHEID GROUND SQUIRREa:. 

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1927. A NEAV POCKET GOPHEK AND A NE"W ANTELOPE GROUND SQUIEREX FROM 

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1931. TWO NEW GROUND SQUIRRBXS FROM LOWER CALIFORNIA, MEXICO. SaU 

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1937. DESCRIPTIONS OF NEAV MAMMALS FROM ARIZONA AND SONOEA, MEXICO. 

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1932. THE STRIPED GROUND SQIHRHEL, CHIRPER OF THE PRAIRIES. Home GeOg. 

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1918. A HISTORY OF GROUND SQUIRREL CONTROL IN CALIFORNIA. Calif. State 

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1929. DENIZENS OF THE MOUNTAINS. 168 pp., iUus. Springfield, 111., and 

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1923. A BREEDING RECORD OF CITELLUS MOLLIS. JouT. IMammal. 4 : 191. 
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1922. an obse3{vation of the carnivorous propensities of the gray gopher. 
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1917. the habits of the thirteen-lined ground squirrel ( citellus 

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N. Dak. Univ. Quart. Jour. 7 : 261-271, illus. 

1925. SOME CONDITIONS AFFl'XTINO THE HIBERNATION OK THE THIRTEEN-LINED 

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1927. THE INFLUENCE OF PRECOOLING. CASTRATION, AND BODY AVEIGHT ON THE 

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1928. HIBERNATION OF THE THIRTEEN-LINED GROUND SQUIRREL, CITEIXU8 

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1929b. HIBERNATION OF THE THIRTEEN-LINED GROUND SQUIRREL, CITELLUS 
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57: 107-129. 



222 NORTH AMERICAN FAUNA [No. 5G 

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1930. HIBERNATION OF THE THIRTEEN-LINED GROUND SQUIRREL, CITEiLLUS TRI- 

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HIBERNATION. Biol. Bull. 59 : 114-127. 

1931. HIBERNATION IN MAMMALS. Quart. Rcv. Biol. 6 : 439-461. 
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1933. THE SE:XUAL cycle of the THIRTEEN-LINED ground squirrel in THE 

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, and Hanawalt, Virginia Brands. 

1930. hibernation of the thirteen-j:,ined ground squirrel, citejllus tri- 
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1931. LABORATORY REPRODUCTION STUDIES ON THE GROUND SQUIKREXS. CITELLUS 

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1930. common injurious mammals of Minnesota. Minn. Agr. Expt. Sta. 

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Kashkarov, D., and Lein, L. 

1927. the yellow ground squirrel of turkestan, cynomys fulvus 

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Kellogg, Eugene S. 

1931. THE CALIFORNIA GROUND SQUIRREL PROGRAM. Calif. Dept. Agr., SpeC. 

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1912. PLEISTOCENE RODENTS OF CALIFORNIA. Calif. Univ. Pubs., Geol. 7: 
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1935. RODENT PLAGUE IN CALIFORNIA. Jour. Aiuer. Med. Assoc. 105 : 856- 
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1857. THE QUADRUPEDS OF ILUNOIS INJURIOUS AND BENEJFIOTAL TO THE 

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1905. KANSAS MAMMALS IN THEIR RELATION TO AGRICULTURE. KaUS. State 

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1928. migratory movement of citellus columbianus in caribou district, 

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1911. a plague-like disease of rodents. U. S. Pub. Health and Marine 

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1912. FURTHER OBSERVATIONS ON A PLAGUE-LIKE DISEASE OF RODENTS WITH 

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1933. A PARASITOLOGICAL SURVEY OF THE GENUS CITELLUS IN MANITOBA. 

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1938] REVISION OF THE GROUND SQUIRRELS 223 

Maiixiabd, Joseph. 

1932. ground squirbels invading new terkitory in ihe san feancisco 
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1896. preliminary diagnoses of new mammals from the mexican border 

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1907. MAMMALS OF THE MEXICAN BOUNDARY OF THE UNITED STATES. U. S. 

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1888. description of a new spekmophile from california. auu. n. y. 

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1889. DESCRIPTIONS OF FOURTEEN NEW SPECIES AND ONE NEW GENUS OF NORTH 

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lS90a. RESULTS OF A BIOLOGICAI. SUR\T':Y OF THE SAN IBANCISCO MOUNTAIN 
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Fauna 3, 136 pp., illus. 

1890b. DESCRIPTIONS OF TWENTY-SIX NEW SPECIES OF NORTH AMERICAN 

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1891. RESULTS OF A BIOLOGICAL RECONNAISSANCE OF SOUTH-CENTRAL IDAHO. 

North Amer. Fauna 5, 132 pp. illus. 

1892. THE GEOGRAPHIC DISTRIBUTION OF OFF IN NORTH AMERICA WITH SPECIAL 

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1893. DESCRIPTIONS OF EIGHT NEW GROUND SQUIRRELS OF THE GENERA SPERM 0- 

PHILUS AND TAMIAS FROM C-NLIFOENIA, TEXAS, AND MEXICO. Blol. 

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lS95a. THE EARLIEST GENERIC NAME OF THE GROUND SQUIRRELS COMMONLY 

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1895b. THE GENEKio NAME ANisoNYX PREOCCUPIED. Scieuce (n. s. ) 2: 107. 

1897. NOTES ON THE CHIPMUNKS OF THE GENUS EUTAML\S OCCURRING WEST OF 

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NEW FORMS. Biol. Soc. Wash. Proc. 11 : 189-212. 

1898. DESCRIPTIONS OF SIX NEW GROUND SQUIRRELS FROM THE WESTERN UNITED 

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1900. DESCRIPTIONS OF TW'EXTY-SIX NEW MAMMALS BTJOM ALASKA AND BRITISH 

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1901a. TV/O NEW RODENTS FROM NORTHWESTERN CALIFORNIA. Biol. SOC. Wasll. 

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1901b. SEVEN NEW MAMMALS FROM MEXICO. INCLUDING A NEW GENUS OF 

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1903a. EIGHT NEW MAMMALS FROM THE UNITED STATES. Biol. SoC. Wash. 

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1903b. FOUR NEW MAMMALS. INCLUDING A NEW GENUS (TEA.NOPUS), FROM 

MEXICO. Biol. Soc Wash. Proc 16: 79-82. 

1908. CALIFORNIA GROUND SQUIRRELS. U. S. Pub. Health and IMarine Hos- 
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1910. THE CALIFORNIA GROUND SQUIRREL. U. S. Bur. Biol. Survey Cir. 76, 
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1913. SIX NEW GROUND SQUIRRELS OF THE CITELLUS MOLLIS GROUP FROM IDAHO, 

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1925. THE pliocene rattlesnake formation and fauna of EASTICRN OREGON, 
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Meyer, Karl F. 

1936. THE sylvatic PLAGUE COMMITTEE. Auicr. Jour. Pul). Health 26 : 961-969. 
Miller, Gerrit Smith, Jr. 

1924. LIST OF NORTH AMERICAN RECENT MAMMALS, 102.!. U. S. Natl. Mu.«i. 

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1935. A PREDATORY SQuiRREHL,. Jour. Manuual. 16: 324. 
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1821. descriition of two mammiferous animals of north AMERICA. Med. 
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1934. ON THE control op REPRODUCTIVE ACTIVITY IN AN ANNUAL-BREEDING 
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224 NORTH AMERICAN FAUNA [No. 56 

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1932. THE MALE REPEODUCTIVB TRACT OF THE SCITJRIDAE. Amer. Jour. Anat. 

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1898. WHAT IS sciuRus variegatus eexleeen? Science (n. s.) 8: 897-898. 

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1900. results of a eiologicat. reconnoissance of the yukon river region. 

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1904. A BIOLOGICAL RECONNAISSANCE OF THE BASE OF THE ALASKA PENINSULA 

North Amer. Fauna 24, 86 pp., illus. 

1909. BIOLOGICAL INVESTIGATIONS IN ALASKA AND YUKON TERRITORY. North 

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1915. THE FUR seals AND OTHER LIFE OF THE PRIBILOF ISLANDS, ALASKA, IN 

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1902. A BIOLOGICAL INVESTIGATION OF THE HUDSON BAY REGION. North Amer. 

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1908. A BIOLOGICAL INVESTIGATION OF THE ATHABASKA-MACKENZIE REGION. 

North Amer. Fauna 27, 574 pp., illus. 

1911. A LIST OF THE MAMMALS NOTED ON THE SETON EXPEDITION OF 1907. In 

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1817. descriptions of seven new genera of north american quadrupeds. 

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1896. NEW SUBSPECIES OF THE GRAY FOX AND SAY'S CHIPMUNK. Acad. Nat. 

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1825. APPENDIX TO captain parry's journal of a second voyage for the 

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BRITISH AMERICA. Pt. 1. 300 pp., illus. London. 
Ross, Beirnard Rogan. 

1861. AN ACCOUNT OF THE ANIMALS USETTTL IN AN ECONOMIC POINT OF VIEW 

TO THE VARIOUS CHiPEWYAN TRIBES. Canad. Nat. and Geol. 6: 433- 
441. 
Sabine, Joseph. 

1822. accounts of the marmots of north america hitherto known, with 

NOTICES AND DESCRIPTIONS OF THREE NEW SPECIES. LiuU. SoC. London 

Trans. 13 : 579^591, illus. 
Sawyer. Edmund Joseph. 

1925. badger runs down ground squirrels. Jour. Mammal. 6 : 125. 



1938] REVISION OF THE GROUND SQUIRRELS 225 

Say, Thomas, [in Edwin James]. 

1823. account of an expedition from Pittsburgh to the rocky mountains, 
performed in the years 1819, 1820 . . . under the command of 

major STEPHEN H. LONG. V. 2, 442 pp. 
SCHEFFER, ThEOPHILUS H. 

1936. AESTTV^ATION AND HIBERNATION PERIOD OF THE SMALLER GROUND SQUIRRELS 
IN THE PASCO-KENNBTWICK COUNTRY, EASTERN M'ASHINGTON. MuiTelet 

17: 17-18. 
Seton, Ernest Thompson. 

1911. THE ARCTIC PRAIRIES. 415 pp., illus. New York. 

1928. LIVES OF GAME ANIMALS. V. 4, 440 pp., iUus. Garden City, N. Y. 
Sharsmith, Carl. 

1936. CARNIVOROUS HABITS OF THE BELDING GROUND [SQUIRREL]. Yosemlte Nat. 

Notes. 15: 12-14. 
Shaw, William Thomas. 

1918. the columbian ground squirrel (citellus columbia.nus columbi- 
ANUS). Calif, state Comu. Hort. Montlily Bull. 7:710-720, illus. 

1920. THE COST OF A SQUIRREL AND SQUIRREL CONTROL. Wash. Agr. Expt. Sta. 

Pop. Bull. 118, 19 pp., illus. 

1921. MOISTURE AND ALTITUDE AS FACTORS IN DETEIRMINING THE SEASONAL 

ACTIVITIES OF THE TOWNSEND GROUND SQUIRREL IN WASHINGTON. 

Ecology 2 : 189-192, illus. 

1924. THE HOME LIFE OF THE COLUMBIAN GROUND SQUIRREL. Cauad. Field Nat. 

38: 128-130, 151-153, illus. 

1925a. DURATION OF THE AESTIVATION AND HIBERNATION OF THE COLUMBIAN 
GROUND SQUIRREL (CITEILLU& COLUMBIANUS) AND SEX RBXATION TO THE 

SAME. Ecology 6: 75-81, illus. 

1925b. THE HIBERNATION OF THE COLUMBIAN GROUND SQUIRREL. Caiiad. Field 

Nat. 39: 56-61, 79-82, illus. 

1925c. THE SEASONAL DIFFERENCES OF NORTH AND SOUTH SLOPES IN CONTROL- 
LING THE ACTIVITIES OF THE COLUMBIAN GROUND SQUIRREL. EcOlOgy 

6: 157-162, illus. 

1925d. BREEDING AND DEVELOPMENT OF THE COLUMBIAN GROUND SQUIRREL. 

Jour. Mammal. 6: 106-113. illus. 

1925e. THE COLUMBIAN GROUND SQUIRREL AS A HANDLER OF EARTH. Sci. 

Monthly 20: 483-490, illus. 

1925f. TRACKING THE COLUMBIAN GROUND SQUIRREL TO ITS BURROW. Natl. 

Geogr. Mag. 47: 587-596, illus. 
1925g. THE FOOD OF GROUND SQUIRRELS. Amcr. Nat. 59 : 250-264, illus. 

1925h. A LIFE HISTORY PROBLEM AND A MEANS FOR THE SOLUTION. Jour. 

Mammal. 6: 157-162, illus. 

19251. OBSERVATIONS ON THE HIBERNATION OF GROUND SQUIRRELS. JOUr. Agr. 

Research 31 : 761-769, illus. 

1926a. A SHORT 8E.\S0N AND ITS EFFECT UPON THE PREPARATION FOR REPRODUC- 
TION BY THE COLUMBIAN GROUND SQUIRREL. ECOlOgy 7 : 136-139, 

illus. 

1926b. AGE OF THE ANIMAL AND SLOPE OF THE GROUND SURFACE. FACTORS MODI- 
FYING THE STRUCTURE OF HIBERNATION DENS OF GROUND SQUIRRELS. 

Jour. Mammal. 7 : 91-96, illus. 

1926c. THE STORING HABITS OF THE COLUMBIAN GROUND SQUIRREL. Anier. Nat. 

60: 367-373. 
Slack, J. H. 

1861. DESCRIPTION OF A NEW SPECIES OF RODENT OF THE GENUS SPERMOPHILUS. 

Acad. Nat. Sci. Phila. Proc. 1861 : 314. 
Sleogs, Geokgb Frederick. 

1026. the adult anatomy and histology of the anal glands of the rich- 
ardson ground squirrel, citkllus richardsonii sabine. auat. rec. 
32: 1-43. 
Stephens, Frank. 

1906. CALIFORNIA MAMMALS. 351 pp., iUus. Sau Diego. 
Stonex Witmek. 

1908. THE MAAfMALS OF NEW JERSEY. N. J. State Mus. Auu. Rept. 1907, 211 
pp., illus. 
Storer, Tracy Irwin. 

1029. SXTMMER and autumn breeding OF the CATJFORNIA GROUND SQIHRREX, 

Jour. Manuunl. 10: 2.3.")-23(!. 



226 NORTH AMERICAN FAUNA [No. 56 

Strong, Richabd Peabson. 

1923. kesearch in some aspects of disease associated with the fields of 

GEiOLOGY, ENTOMOLOGY, AND PAKAsiTOLOGY. Science (n. s. ) 57: 
507-520. 

SUBBEB, THADDEUS. 

1932. THE MAMMALS OF MINNESOTA. 84 pp. illus. St. Paul. (Bull. Minn. 

Dept. Conserv., Div. of Game and Fish). 

SVIHLA, AbTHTJB. 

1931. oallospebmophilus climbing tbees. Murrelet 12 : 80'. 

1933. OCCUBBENCEI OF A COLONY OF ALBINO GBOUND SQUIRREILS NEAR PULLMAN, 

WASHINGTON. Murrclct 14 : 78. 

SWABTH, HaBEY SCHEXWALD. 

1929. THE FAXJNAL AREIAS OF SOUTHERN ABIZONA : A STUDY IN ANIMAL DISTRI- 
BUTION. Calif. Acad. Sci. Proc. (4) 18 : 267-383, illus. 
Taylob, Walter Penn. 

1910. TWO NEW RODENTS FROM NEivADA. Calif. Univ. Pubs., Zool, 5 : 283-302, 

illus. 

1911. MAMMALS OF THE ALEXANDER NEVADA EXPEDITION OF 1909. Calif. UniV. 

Pubs., Zool. 7 : 205-307. 

1916. A NEW SPERMOPHILE FROM THE SAN JOAQUIN VALLEY, CALIFORNIA, WITH 
NOTES ON AMMOSPEEMOPHILUS NELSONI MEBRIAM. Calif. UniV. 

Pubs., Zool. 17: 15-20, illus. 
Thomas, Oldfiesld. 

1915. THE PENIS-BONE, OR "BACULUM", AS A GUIDE TO THE CLASSIFICATION OP 

CERTAIN SQUIRRELS. Ann. and Mag. Nat. Hist. (8) 15:383-387. 

1927. A SELECTION OF LEICTOTTPES OF AMERICAN BODENTS IN THE COLLEiCTION 

OF THE BBiTisH MUSEUM. Ann. and Mag. Nat. Hist. (9) 19: 545-554. 
Town SEND, John Kirk. 

1839. NARRATIVE OF A JOURNEY ACROSS THE ROCKY MOUNTAINS TO THE COLUM- 
BIA BIVEB, AND A VISIT TO THE SANDWICH ISLANDS, CHILI, &C. WITH A 

sciENTTFic APPENDIX. 352 pp. Philadelphia. 
Wade, Otis. 

1927. breeding habits and eably life of the thirteen-striped ground 

SQUIRREL, CITELLUS TBIDECEMUNEATUS (MITCHILL) . JOUT. Mammal. 

8: 269^276. 

1980. THE BEHAVIOR OF CERTAIN SPEBMOPHILES WITH SPECIAL EEFEBENCE TO 

AESTIVATION AND HiBEatNATiON. Jour. Mammal. 11 : 160-188. 
Ward, Henry L. 

1891. DESCRIPTION OF TWO NEW SPECIES OF BODENTS FBOM MEXICO. Amer. Nat. 

25: 158-161. 
Warren, Edward Royal. 

1910. THE MAMMALS OF COLORADO. 300 pp., illus. New York. 

1924. GROUND SQUIRRELS AND WEASELS. JouT. Mammal. 5 : 265. 
Wood, Frank Elmer. 

1910. a study of the mammals of champaign county, illinois. 111. state 
Lab. Nat. Hist. Bull. 8 : 501-613, illus. 



Plate 14 

(Natural size) 

A. Citellus (CaUospermophilus) saturatus. 

B. Citellus {Poliocitelliis) franklinii. 

C. Citellus (Ictidomys) tridecemlineatus. 

D. Citellus (Xerospennophilus) mohavensis. 

E. Citellus {Citellus) citellus. 

F. Citellus (Citellus) fulvus. 

G. Cynomys (Cynomys) ludovicianus. 
H. Citellus {Citellus) parryii. 

228 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



Plate 14 




Skulls of citellus and cynomys. 



North American Fauna No. 56, U. S. Dept. of Agriculture. Biological Survey 



PLATE 15 




Skulls of Glaucomys. tamias. Eutamias. Sciurus, Microsciurus and 

ClTELLUS. 



Plate 15 
(Natural size) 

A. Olaucomys volans volans. 

B. Tamias striatus. 

C. Eutamias (Neotamias) dorsaUs. 

D. Microsciurtis browni. 

E. Citellus {AmiHOspennophilus} harrisii. 

F. Citellus iOtoftpermophilus) variegatus grammurus. 

G. Seiurus ( HeHprrosriuni-s)grixrux. 
H. Sciurus (Neosciurus) carolinensis. 

229 



Plate 16 

(Natural size) 

A. Syntheosciunis brochns. 

B. Sciurus (GuerlingMetus) aestuans cMriquensis. 

C. Sciurus (Parasciurus) niger limitis. 

D. Tamiasciurus douglasii. 

E. Sciurus (Otosciurus) aberti. 

F. Sciurus (Sciurus) vulgaris. 

230 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 16 




Skulls of Sciurus, Tamiasciurus, and Syntheosciurus. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 17 




Skulls of citellus and cynomys 



Plate 17 



(Natural size) 

A. Citellus (CalJosprrDiopJiiltis) saturatus- 

B. CitvUu.'i iPoliofitcllKs) fnmkUiiii. 

C. Citellus (Ictidonn/s) tritlecemliiicatus. 

D. Citcllua ( Xcrosprrniopli ilus) mohavensis. 

E. Citellus iCitrllii.s) citrlhis. 

F. Citellus {Citellus) fulrus. 

G. Cynomys (Cytioinys) ludorieiainis. 
H. Citellus {Citellus) pnrryii. 



231 



Plate IS 
(Natural size) 

A. Glaucomys voians volaiis. 

B. Tamias striatus. 

C. Eutaniias (Neotamias) dorsalis. 

D. Microsciurtis hrowni. 

E. Citellus {Aminospermopliilus) harrisii. 

F. Citellus (OtospermopJiilus) variegatus grammnrus. 

G. Sciiirus (Hesperosciurus) griseus. 
H. Sckirus (Neosciiirus) carolinensis. 

232 



North American Fauna No. 56, U. S. Dept. of Agriculture. Biological Survey 



PLATE 18 




Skulls of Glaucomys. tamias. eutamias. Sciurus, Microsciurus, and 

ClTELLUS. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 19 




SKULLS OF SCIURUS. TAM I ASCI URUS, AND SYNTHEOSCI U RUS. 



Plate 19 

(Natural size) 

A. Synthcosciuriis brochus. 

B. Sciurus {G-uerlinguetus) aestuans chiriquensis. 

C. Sciurus (Parasciurus) niger limitis. 

D. Tamiasciurus douylasii. 

E. Sciurus {Otosciurus) abcrti. 

F. Sciurus (Sciurus) vulgaris. 

233 



Plate 20 

(Natural size* 

A. Cynomys (Ci/noniys) ludoviciantis. 

B. Citellus {Xerospermophiliis) mohavensis. 

C. Citellus (CallospermophUus) saturatiis. 

D. Citelhis {Citellus) citellus. 

E. Citellus (Poliocitellus) franklinii. 

F. Citellus (Citellus) parryii. 

G. Citellus (Citellus) fulvus. 

H. Citellus (Ictidomys) tridecemlineatus. 
234 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



Plate 20 



^^^^^^m '* ^^^^1 


^^^^^^r "* fl 


^^^^^^^^^^^^^r ^^1 




^r ^ 1 


^^^V '-'^ fl 






H^^^^^B I^^^H 




M 


^^^^^m ^%*3^^B 




^^^1 


















^^^H 


^^v "* .^^H 




H 


UJ 




1 





North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



Plate 21 




Plate 21 
(Natural size) 

A. Sciiirus (Hcipcrosci lints) grincuH. 

B. Microsci lints hroinii. 
V. Glaiicomys volans. 

D. Citellits (AniiiiospennopJiilus) han-isii. 

E. Tamias stiiaiiix. 

F. i^ciitrus (Xcoxciiinis) caroJiurnsis. 

G. CltelluH {Otoxiicniiit/jhiliis) ritrietjatita ijnniuininis. 
H. Eutaniias (NvotumiiDi) dorsalis. 

235 



Plate 22 

(Natural size) 



A. Bciurus (Otosciunis) aberti. 

B. Sciurus (Parasciiirtis) niger. 

C. Syntheoscmrus hrochus. 

D. Sciurus (Sciurus) rulgaris. 

E. Tamiasciurus dougJasii. 

F. Sciurus (Guerlinguetiis) aestuaus. 

236 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 22 




North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 23 




Skulls of citellus. 



Plate 23 

(Natural size) 

'A. Citelhis toinisevdii niolli.'i. S ad., Fairfield, Utah (no. 30144, U. S. Natl. Mus., 
Biological Survey collection ) . 

B. Citcllus idahoriisi.s. $ ad.. Nanipa. Idaho (no. lG8r.ll, IT. S. Natl. Mus., 

Biological Survey collection). 

C. Citcllus va.fhiii!/t()iii inixhiiKjtoiii. S ad.. Wallnla. Wa.'^h. (no. Li:>r)732, U. S. 

Natl. Mu.s., Biological Survey collection). 

D. Citcllus hruinicus, S ad., Weiser, Idaho (no. 201725. U. S. Natl. Mu.x., Bi- 

ological Survey collection). 

E. Citcllus bcldin(/i htltliii(/i. S ad., Mannuoth Pass, Calif, (no. 42025. U. S. 

Natl. Mus., Biological Survey collection). 

F. Citcllus avmatus. 6 ad., Barclay, Utah (no. 87791, U. S. Natl. Mu.>^., Bi- 

ological Survey collection). 

237 



Plate 24 

(Natural size) 

A. Citcllus colunibknms coJumhianus, $ ad., Nelson, British Columbia (no. 

66670, U. S. Natl. Mus., Biological Survey collection). 

B. Citellus parryii li/iatiis, S ad., St. Lawrence Island, Bering Sea (no. 57312, 

Mus. Vert. Zool.). 

C. Citellus osgoodi, S ad., Circle. Alaska (no. 128269, U. S. Natl. Mus., Bi- 

ological Survey collection). 

D. Citellus parryii t)lesius, S ad.. Head of Coal Creek, Yukon (no. 134954, U. S. 

Natl. Mus., Biological Survey collection). 
238 



North American Fauna No. 56. U. S. Dept. of Agriculture, Biological Survey 



Plate 24 




SKULLS OF CITELLUS. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



Plate 25 




SKULLS OF CITELLUS. 



Plate 25 

(Natural size) 

A. CifellKX spilosoDW npilosonxi. $ ad.. Chicalote. Agnasoalientes, Mexico (no. 

78!t97, U. S. Natl. Mus., Biological Survey collection). 

B. Citellii-s spUosomn prattiisi.s, 3 sul)adult, Flagstaff, Ariz. (no. 202123, U. S. 

Natl. Miis., liioldgical Survey collection). 

C. CitcUiis mcrirdiitis m<xiruiii(.s, S ad., Silao, Guanajuato, Mexico (no. 79018, 

U. S. Natl. Mus., Biological Survey collection). 

D. Citelhis peroten.'iis, $ ad.. Perote, Vera Cruz (no. 54265, U. S. Natl. Mus., 

Biological Survey collection). 

E. CitcUuK: rirhanhsoiiii clef/tuis. S ad.. Pinedale, Wyo. (no. 176905, U. S. Natl. 

Mus., Biological Survey collection). 

F. Citelhis richdfd.sonii ricliiird.sonii. £ ad.. Wingard. Sask.-itchewan (no. 
7:>644. U. S. Natl. Mus., Biological Survey coll<>etion). 

239 



Plate 26 

(Natural size) 

A. Citelhts ieecheiji parvidus, $ subadult. Loue Pine, Calif, (no. 32553, U. S. 

Natl. Mus., Biological Survey collection). 

B. Citelliis beechei/i douglasii, $ acL, Forest Grove, Oreg. (no. 30887, U. S. 

Natl. Mus., Biological Survey collection). 

C. Citellus varleyatus rupestris, 2 ad. (type), Rio Sestin. Durango (no. 21231, 

Amer. Mus. Nat. Hist.). 

D. Citellus cumulatus atnndatus, $ ad., Manzanillo, Colima. Mexico (no. 44596, 

U. S. Natl. Mus., Biological Survey collection). 
240 



North American Fauna No. 56. U. S. Dept. of Agriculture. Biological Survey 



Plate 25 




SKULLS OF CITELLUS. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 27 




SKULLS OF CITELLUS. 



F'late 27 
(Natural size) 

A. CitcUiis lateralis mitratus, S ad., South YoUa Bolly Mountain, Calif, (no. 

138124, U. S. Natl. Mus., Biological Survey collection). 

B. Citellus ntadrciisis, S ad., Sierra Madre. near Guadalupe y Calvo. Chihuahua. 

Mexico (no. 95357, U. S. Natl. Mus.. Biological Survey collection). 

C. Citellus tercticaiulus tcrcticaiidiis, $ ad.. Fort Yuma, Calif, (no. 99507, 

U. S. Natl. Mus., Biological Survey collection). 

D. Citellus lateralis lateralis, S ad., Hahn.s Peak. Colo. (no. 168865, U. S. Natl. 

Mu8., Biological Survey collection). 

E. Citellus adocefus, $ ad.," La Salada. Michoacan. Mexico (no. 126140, U. S. 

Natl. Mus., Biological Survey collection). 

F. Citellus leueurus leuvurns, $ ad., Caltazon. Calif, (no. 54010, U. S. Natl. 

Mus., Biological Survey collection). 

241 



Plate 28 
(Natural size) 

A. CiteUiis toinisendii mollis, S ad., Fairfield, Utah, (uo. 30144, U. S. Natl. Mus., 

Biological Survey collection). 

B. Citellus, idalioeiisis, $ ad.. Nampa, Idaho (no. 168511, U. S. Natl. Mus., 

Biological Survey collection). 

C. Citellus icashiuytoni ivashiufftoni, $ ad., Wallula, Wash. (no. 235732, U. S. 

Natl.- i\Ius., Biological Survey collection). 

D. Citellus bruiiHeus, $ ad., Weiser, Idaho (no. 201725, U. S. Natl. Mus., Bi- 

ological Survey collection). 

E. Citellus heldiufii heldiiigi, $ ad.. Mammoth Pass, Calif, (no. 42025, U. S. 

Natl. Mus., Biological Survey collection). 

F. Citellus armatus, $ ad., Barclay, Utah (no. 87791, U. S. Natl. Mus., Biologi- 

cal Survey collection). 
242 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 28 




SKULLS OF CITELLUS. 



N orth American Fauna No. 56. U. S. Dept. of Agriculture, Biological Survey 



PLATE 29 




SKULLS OF ClTELLUS. 



Plate 29 

(Natural size) 

4. Citellus columbianus coliiiiihiniiitx. $ ad.. Nelson. British Columbia (no. 
66670, U. S. Natl. Mas., Biological Survey collection). 

B. Citellus parry a lyratiis, $ ad., St. Lawrence Island, Bering Sea (no. 57312, 

Mus. Vert. Zool.). 

C. Citellus osffoodi, S ad., Circle, Alaska ( no. 128369, U. S. Natl. Mus.. Biological 

Survey collection). 

D. Citellus parry a plesius, $ ad.. Head of Coal Creek. Yukon (no. 134954, 

U. S. Natl. Mus., Biological Survey collection). 

243 



Plate 30 

(Natural size) 

A. CiteUiis spilosoma spilosoma, $ ad., Chicalote. Agiiascalientes, Mexico (no. 

78997, U. S. Natl. Mus., Biological Survey collection). 

B. Citelltis spilosoma pratensis, S subadult, Flagstaff, Ariz. (no. 202123, U. S. 

Natl. Mus., Biological Survey collection). 

C. Citelltis mejcicanus mexicanus, S ad., Silao, Guanajuato, Mexico (no. 79108, 

U. S. Natl. Mus.. Biological Survey collection). 

D. Citellus perotensis, $ ad., Perote, Vera Cruz (no. 54265, U. S. Natl. Mus., 

Biological Survey collection). 

E. Citellus richardsonii elegans, S ad., Piuedale, Wyo. (no. 176905, U. S. Natl. 

Mus., Biological Survey collection). 

F. Citellus richardsonii richardsonii, $ ad., Wingard. Saskatchewan (no. 

73644, U. S. Natl. Mus., Biological Survey collection). 
244 



North American Fauna No. 56. U. S. Dept. of Agriculture, Biological Survey 



Plate 30 



A 


B 






c 

A . & 


D 






%^ 


^ry 


A 




■^"^1 




^ ^ -^ 




'■**' 


^^^^^^H 



SKULLS OF CITELLUS. 



North American Fauna No. 56, U. S. Dept. of Agriculture, Biological Survey 



PLATE 3t 




SKULLS OF CITELLUS. 



Plate 31 

(Natural size) 

A. Citc1lii.<< hecrhciii iKirnilii-s. £ subadiilt. Lone Pine. Calif, (no. 32o5?), U. S. 

Natl. Mn.s., Biological Survey collection). 

B. Citellus beech fiji doiiijlaaii, S ad., Forest Grove, Oreg. (no. 30S87, U. S. Natl. 

Mus., Biological Survey collection ) . 

C. Citellus rarief/otiix rupeHtriH, $ ad. (type), Rio Sestin. Durango (no. 21231, 

Amer. Mus. Nat. Hist.). 

D. Citellus animhitus aiiuiilatus. S ad., Manzanillo, Colinia. Mexico (no. 44-596, 

U. S. Natl. :Mus., Biological Survey collection). 

245 



Plate 32 

(Natural size) 

A. Citellus lateralis mitratus, $ ad., South YoUa Bollv Mountain, Calif, (no. 

138124, U. S. Natl. Mus., Biological Survey collection). 

B. Citellus madrensis, $ ad., Sierra Madre, near Guadalupe y Calvo, Chihuahua, 

Mexico (no. 95357, U. S. Natl. Mus., Biological Survey collection). 

C. Citellus tereticaudus tereticaudus, $ ad., Fort Yuma, Calif, (no. 99507, 

TJ. S. Natl. Mus., Biological Survey collection). 

D. Citellus lateralis lateralis, $ ad., Hahus Peak, Colo. (no. 168865, U. S. Natl. 

Mus., Biological Survey collection). 

E. Citellus adocctus, $ ad.. La Salada, Michoacan, Mexico (no. 126140, U. S. 

Natl. Mus., Biological Survey collection). 

F. Citellus leucurus leucurus, $ ad., Cabazon, Calif, (no. 54010, U. S. Natl. 

Mus., Biological Survey collection). 
246 



North American Fauna No. 56. U. S. Dept. of Agriculture, Biological Survey 



PLATE 32 




SKULLS OF CITELLUS. 



INDEX 



[New names and principal page references to a species in boldface; synonyms in italic] 



aberti, Sciurus, 49, 50. 
ablusus, Citellus parrvii, 17, 54, 95, 97, 
98, 100, 101, 102, 103. 

Citellus plesius, 98. 
Acknowledgments, 2. 
adocetus, Citellus, 29 (habits), 44, 164, 
165. 

Otospermophilus, 165. 
adolphei, Sciurus, 49. 
aestuans, Sciurus, 50. 
albertae, Citellus columhianus, 85, 88. 
alfari, Microsciurus, 51. 

Sciurus, 51. 
alleni, Citellus tridecemlineatus, 113, 
114, 115, 116, 117, 118. 

Sciurus, 50. 

Spermophilus tridecemlinentus, 114. 
Ainmospermophilus, 5, 29 (habits), 30, 
35, 39, 44, 45, 53, 54, 166, 182. 

amplus, 182, 183. 

canfieldae, 178. 

cinnamomeus, 174. 

extimus, 179. 

harrisii, 167. 

insularis, 181. 

interpres, 180. 

kinoensis, 169. 

leucurus, 170. 

nelsoni, 182. 

peninsulae, 176. 

pennipes, 175. 

saxicola, 169. 

tersus, 173. 
amplus, Ammospermophilns nelsoni, 182, 

183. 
Anisonyx, 53. 

brachinra, 53, 55, 85. 

canescens, 125. 

cinnamomeus, 174. 

cryptospilotus, 130. 

grammurus, 142. 

harrisii, 167. 

macros pilotus, 125. 

tereticaudus, 187. 
annectens, Citellus spilosoma, 128. 

S pernio philus spilosoma, 128. 
annulatuK, Citellus, 28 (habits), 29, 39, 
46, 55, 162. 

Citellus annulatus, 163, 164, 165. 

Notocitellus, 46. 

Otospermophilus, 163. 

Spermophilus, 44, 55, 163. 
Antelope scjuirrel, 5, 29 (liabits), 35, 39, 
54. 

Colorado, 175. 

Espiritu Santo, 181. 



Antelope squirrel — Continued. 

Grand Canyon, 173. 

gray-tailed, 167. 

mid-peninsular, 178. 

rusty, 174. 

San Joaquin, 182. 

southern peninsular, 179. 

Texas, 180. 

western peninsular, 176. 

white-tailed, 170. 

Yuma, 169. 

See also Ground squirrel. Rock 
squirrel. 
apache, Sciurus, 50. 
apricus, Citellus tereticaudus, 190. 
Araeosciurus, 50. 
Arctomys, 53, 55. 

beecheyi, 55, 148. 

brachyura, 85. 

brachyurus, 85. 

columbianns, 53, 55, 85. 

douglasii, 55, 150. 

erytkrogluteia, 55, 85, 88, 97. 

franklinii, 42, 133. 

hoodii, 55, 107. 

kennicottii, 55, 91, 94. 

lateralis, 191. 

parryi, 88, 91. 

phaeognatha, 55, 91. 

richardsonii, 73. 

tridecemlineata, 107. 
arenicola, Citellus tridecemlineatus, 111, 

113, 116, 118. 
arens, Spermophilus spilosoma, 125. 
arizonae, Citellus tereticaudus, 187, 188. 
arizonensis, Callospermophilus lateralis^ 
196. ■ 

Citellus lateralis, 191, 193, 196, 214. 

Sciurus, 50. 
armatus, Citellus, 10 (habits), 54, 78, 82, 
83, 85. 

Spermophilus, 55, 56, 78. 
artemesiae, Citellus mollis, 63, 65. 

Citellus townsendii, 64, 65. 
asiaticus, Eutamias, 47. 

Sciurus striatus, 47. 
atricapillus, Citellus, 160, 161. 

Citellus variegatus, 161. 

Otospermophilus grammurus, 161. 

Spermophilus grammurus, 161. 
aureogaster, Sciurus, 49. 

badius, Ictidomys tridecemlineatus, 110. 
Spermophilus tridecemlineatus, 110, 
111. 
Baiosciurus, 49. 

247 



248 



NORTH AMERICAN FAUNA 



[No. 56 



barrowensis, Citellus parryii, 94, 95, 99. 

Sper^nophilus, 95. 
beecheyi, Arctomys, 55, 148. 

Citellus, 5, 26, 43, 44, 133. 

Citellus beecheyi, 23 (habits), 28, 
148, 151, 152, 153, 154, 155, 157, 
158, 159, 160, 161, 162. 

Citellus grammurus, 148. 

Citellus variegatus, 148. 

Otospermophilus, 44, 148. 

Otospermophilus grammurus, 148. 

Spermophilus, 148. 

Spermophilus grammurus, 148. 
beldingi, Citellus, 40, 54, 81. 

Citellus beldingi, 11 (habits), 81, 
83, 84. 

Spermophilus, 56, 81. 
bensoni, Citellus, 215. 
beringensis, Citellus parryii, 96. 

Spermophilus, 95. 
bernardinus, Callospermophilus, 209. 

Citellus chrysodeirus, 209. 

Citellus lateralis, 204, 209. 

Spermophilus, 209. 
boothiae, Sciurus, 49. 
boquetensis, Microsciurus, 51. 
hrachiura, Anisonyx, 53, 55, 85. 
hrachyura, Arctomys, 85. 
brachyurus, Arctomys, 85. 
brevicaudus, Spermophilus chrysodei- 
rus, 209. 
brochus, Syntheosciurus, 52. 
brunneus, Citellus, 71, 72. 

Citellus townsendii, 72. 
Bubonic plague, 10, 11, 13, 16, 26. 
buccatus, Sciurus, 136. 
buckleyi, Citellus variegatus, 43, 141, 
144. 

Otospermophilus grammurus, 141. 

Spermophilus, 55, 141. 

Spermophilus grammurus, 141. 
buxtoni, Citellus, 3, 100, 102. 

Citellus parryii, 100. 

Callospermophilus, 5, 31 (habits), 35, 
39, 45, 53, 54, 190, 215. 

arizonensis, 196. 

bernardinus, 209. 

caryi, 197. 

castanurus, 201. 

certus, 208. 

chrysodeirus, 203, 215, 216. 

cinerascens, 198, 199. 

connectens, 205. 

lateralis, 43, 192. 

madrensis, 213. 

mitratus, 210. 

perpallidus, 206, 207. 

saturatus, 212. 

tescorum, 199. 

trepidus, 206. 

trinitatis, 211. 

wortmani, 195. 
canescens, Anisonyx, 125. 

Citellus spilosoma, 124, 125, 126, 
129. 

Spermophilus, 125. 

Xerospermophilus, 125. 



canfieldae, Ammospermophilus leucurus, 
178. 

Citellus leucurus, 177, 178, 179. 
canus, Citellus mollis, 67. 

Citellus townsendii, 61, 64, 66, 
67, 71. 

Spermophilus mollis, 67. 
captus, Citellus beecheyi, 216. 
carolinensis, Neosciurus, 51. 

Sciurus, 48, 49, 50, 51. 
caryi, Callospermophilus lateralis, 197. 

Citellus lateraUs, 193, 195, 197, 202. 
castanurus, Callospermophilus, 201. 

Citellus, 201. 

Citellus lateralis, 192, 193, 197, 198, 

199, 201, 203, 205, 207. 
Spermophilus, 201. 
Tamias, 201. 

certus, Callospermophilus lateralis, 208. 

Citellus laterahs, 204, 208. 
Chickaree, 51. 
Chipmunk, 35, 52. 

eastern, 46, 47. 

western, 47. 
chlorus, Citellus, 188. 

Citellus tereticaudus, 188. 
chrysodeirus, Callospermophilus, 203, 
215, 216. 

Citellus, 203, 215, 216. 

Citellus lateralis, 194, 198, 203, 205, 
207, 208, 209, 210, 211, 212, 213. 

Spermophilus, 203. 

Tamias, 203. 
cinerascens, Callospermophilus, 198, 199. 

Citellus, 198, 199. 

Citellus laterahs, 192. 197. 198. 190. 

200, 201, 202. 
Spermophilus, 198. 
Tamias, 198. 
Tamias lateralis, 198. 

cinereicollis, Eutamias, 48. 
cinnamomeus, Amm,ospermophilus leu- 
curus, 174. 

Anisonyx leucurus, 174. 

Citellus leucurus, 167, 168, 171, 172, 
173, 174, 175, 176, 180, 181, 182. 

Spermophilus leucurus, 174 

Tamias leucurus, 174. 
citellus, Citellus, 2, 40, 54. 

Mus, 39, 40, 53. 
Citellus, 39 (genus), 40 (subgenus). 

ablusus, 17, 54, 95, 97, 98, 100, 101, 
102, 103. 

adocetus, 29 (habits), 44, 164, 165. 

albertae, 85, 88. 

alleni, 113, 114, 115, 116, 117, 118. 

annectens, 128. 

annulatus, 28 (habits), 29, 39, 46. 
55, 162, 163, 164, 165. 

apricus, 190. 

arenicola, 111, 113, 116, 118. 

arizonae, 187, 188. 

arizonensis, 191, 193, 196, 214. 

armatus, 10 (habits), 54, 78, 82, 
83, 85. 

artemesiae, 63, 64, 65. 

atricapillus, 160, 161. 

barrowensis, 94, 95, 99. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



249 



Citellus — Continued. 

beecheyi, 5, 23 (habits), 26, 28, 43, 
44, 133, 148, 151, 152, 153, 154, 

155, 157, 158, 159, 160, 161, 162. 
beldingi, 11 (habits), 40, 54, 81, 

83, 84. 
bensoni, 215. 
beringensis, 96. 
bernardinus, 204, 209. 
brunneus, 71, 72. 
bucklevi, 43, 141, 144. 
buxtoni, 3, 100, 102. 
canescens, 124, 125, 126, 129. 
canfieldae, 177, 178, 179. 
canus, 61, 64, 66, 67, 71. 
captus, 216. 

carvi, 193, 195, 197, 202. 
castanurus, 192, 193, 197, 198, 199, 

201, 203, 205, 207. 
certus, 204, 208, 
chlorus, 188. 
chrvsodeirus, 194, 198, 203, 205, 

207, 208, 209, 210, 211, 212, 213, 

215, 216. 
cinerascens, 192, 197, 198, 199, 200, 

201, 202. 
cinnamomeus, 167, 168, 171, 172, 

173, 174, 175, 176, 180, 181, 182. 
citellus, 2, 40, 54. 
cochisei, 215. 
columbianus, 5, 13 (habits), 54, 85, 

89, 90, 98. 
connectens, 201, 205. 
couchi, 140. 

couchii, 137, 138, 139, 141, 143. 
cryptospilotus, 129, 130. 
douglasi, 150. 
douglasii, 27 (habits), 148, 150, 155, 

216. 
elegans, 5, 10 (habits), 11, 68, 74, 

75, 76, 77, 79, 80, 81, 82, 83, 132. 
eremonomus, 185, 186. 
erythrogluteius, 97, 98. 
eversmanni, 54. 
extimus, 177, 178, 179, 181. 
fisheri, 28, 150, 151, 152, 153, 154, 

156, 157, 158, 216. 
franklini, 133. 

franklinii, 3, 5, 21 (habits), 41, 42, 

43, 44, 133, 215. 
fulvus, 54. 
goldmani, 164. 
grammurus, 23, 43, 45, 55, 137, 139, 

140, 141, 142, 146, 147, 148. 
guttatus, 71. 
harrisi, 167. 

harrisii, 167, 170, 171, 172. 
hollisteri, 115, 117. 
idahoensis, 6 (habits), 54, 63, 68, 

69, 72. 
insularis, 164, 181. 
interpres, 169, 176, 180. 
juglans, 142, 144. 
kadiacensis, 103. 
kennicotti, 91. 
kennicottii, 91. 



Citellus — Continued. 

kodiacensis, 97, 99, 100, 103. 
laterahs, 43, 55, 191, 195, 196, 197, 

198, 201, 202, 203, 212, 213, 214. 
leucurus, 168, 169, 170, 173, 174, 

175, 176, 177, 178, 179, 180, 182. 
leurodon, 63, 64. 
loringi, 71. 

lyratus, 97, 99, 101, 103. 
macrospilotus, 125. 
madrensis, 46, 191, 213. 
major, 126, 128, 129, 130, 131. 
mexicanus, 5, 20 (habits), 41, 42,43, 

54, 119, 121, 122,215, 216. 
microspilotiis, 125. 
mitratus, 204, 210, 212. 
mohavensis, 30 (habits), 183, 185. 
mollis, 5, 6, 7, 45, 54, 63, 65, 66, 67, 

68, 72, 106, 183, 184, 185, 186. 
monticola, 116, 118. 
nebulicola, 100, 102. 
neglectus, 186, 187. 
nelsoni, 182. 
nesioticus, 160. 
nevadensis, 77, 79. 
nudipes, 150, 157, 158, 160. 
obsoletus, 127, 130. 
oregonus, 5, 12 (habits), 41, 43, 77, 

79 80 82 83. 
osgoodi', 17 (habits), 54, 92, 98, 104. 
pallescens, 124, 125, 126, 132. 
pallidus, 109, 111, 112, 115, 118. 
parry i, 91. 
parrvii, 3, 16 (habits), 38, 39, 54, 

5o, 90, 91, 95, 96, 97, 98, 99, 100, 

104, 105, 136. 
parvidens, 119, 121. 
parvulus, 150, 155, 156, 158, 159, 

160. 
parvus. 113, 115, 117. 
peninsulae, 166, 176, 178, 179. 
pennipes, 175. 
perotensis, 21, 41, 42, 132. 
pessitnus, 65. 
plesius, 16, 17, 86, 87, 88, 92, 97, 99, 

100, 105, 133. 
pratensis, 128, 130. 
quatalensis, 214, 215. 
richardsoni, 73. 
richardsonii, 5, 8 (habits), 54, 73, 

76, 77, 78, 79, 81, 85, 86. 
ridgwayi, 215. 
ruficaudus, 88, 89. 
rupestris, 137, 138, 140, 141, 144. 
rupinaruni, 159. 
saturatus, 191, 203, 212. 
saxicola, 169. 
sierrae, 153, 155. 
spilosoma, 5, 20 (habits), 31, 41, 42, 

55, 70, 120, 122, 124, 126, 131, 
132. 

stejnegeri, 3. 
slonei, 98, 100. 
taylori, 216. 

tereticaudus, 30 (habits), 41, 45, 
184, 185, 187, 189, 190. 



250 



NORTH AMERICAN FAUNA 



[No. 56 



Citellus — Continued. 

tersus, 173. 

tescoriim, 198, 199, 206, 212, 213. 

texensis, 107, 109, 110, 111, 122. 

townsendi, 216. 

townsendii, 5 (habits), 55, 60, 69, 
70 71 73 

trepi'dus,' 201, 202, 204, 206, 208. 

tridecemlineatus, 3, 5, 18 (habits), 
21, 31, 41, 42, 54, 106, 107, 110, 
113, 115, 118, 119, 216. 

trinitatis, 210, 211. 

tuitus, 215. 

tularosae, 145. 

Utah, 144, 146. 

variegatus, 22 (habits), 54, 55, 136, 
138, 140, 146. 

vigilis, 61, 66, 67, 68. 

vinnulus, 170. 

vociferans, 185, 186. 

Washington!, 5, 6, 7 (habits), 54, 62, 
63, 69, 71, 72, 73, 106, 107, 216. 

washoensis, 63, 64. 

wortmani, 191, 193, 195. 

yakimensis, 60, 63. 
Citillus, 53. 

mexicanus, 119. 
citillus, Mus, 53. 
cochisei, Citellus, 215. 
coUiaei, Sciurus, 49. 
Colobates, 53. 
Colobotis, 53, 54. 

columbianus, 85. 

franklinii, 54. 

hoodii, 54. 

kennicotti, 91. 

parry i, 91. 

richardsonii, 54. 

tridecemlineatus, 54. 
Colored plates, explanation of, 2. 
columbianus, Arctomys, 53, 55, 85. 

Citellus, 5, 13 (habits), 54, 85, 98. 

Citellus columbianus, 85, 89, 90. 

Colobotis, 85. 

Spermophilus, 85. 
concolor, Sciurus, 50. 
connectens, Callospermophilus chryso- 
deirus, 205. 

Citellus lateralis, 201, 205. 
couchi, Citellus variegatus, 140. 
couchii, Citellus variegatus, 137, 138, 
139, 141, 143. 

Otospermophilus, grammurus, 140. 

Spermophilus, 55, 139. 

Spermophilus grammurus, 139. 
Cranial measurements, explanation of, 

59. 
cryptospilotus, Anisonyx, 130. 

Citellus spilosoma, 129, 130. 

Spermophilus, 130. 

Xerospermophilus, 130. 
Cynomys, 35, 38, 39. 

gunnisoni, 55, 88. 

ludovicianus, 38. 

socialis, 38. 



deppei, Sciurus, 49. 
Diseases — 

Bubonic plague, 10, 11, 13, 16, 26. 

Rocky Mountain spotted fever, 16. 

Tularemia, 6, 26, 27. 
dorsalis, Eutamias, 48. 
douglasi, Citellus beecheyi, 150. 

Citellus variegatus, 150. 
douglasii, Arctomys, 55, 150. 

Citellus, 216. 

Citellus beecheyi, 27 (habits), 148, 
150, 155. 

Otospermophilus grammurus, 151. 

Spermophilus, 150. 
douglassi, Spermophilus grammurus, 150. 
durangi, Sciurus, 50. 

Echinosciurus, 48, 49. 
elegans, Citellus, 10, 11, 76. 

Citellus richardsonii, 5, 10 (habits), 
68, 74, 75, 76, 77, 79, 80, 81, 82- 
83, 132. 

Spermophilus, 55, 56, 62, 76. 

Spermophilus richardsoni, 76. 
empetra, Mus, 91. 

Spermophilus, 56, 91. 
eremonomus, Citellus, 185, 186. 
erythroglutaeus, Spermophilus empetra, 

85. 
erythrogluteia, Arctomys, 55. 

Arctomys parryi, 85, 88, 97. 

Spermophilus parryi, 85. 
erythrogluteius, Citellus, 97, 98. 
Eutamias, 35, 39, 44, 46, 47, 52. 

asiaticus, 47. 

cinereicollis, 48. 

dorsalis, 48. 

frater, 48. 

sonomae, 48. 
eversmanni, Citellus, 54. 

Spermophilus, 53. 
extimus, Ammospermophilus leucurus, 
179. 

Citellus leucurus, 177, 178, 179, 181. 

Fever, Rocky Mountain spotted, 16. 
fisheri, Citellus beecheyi, 28, 150, 151, 
152, 153, 154, 156, 157, 158, 216. 

Citellus variegatus, 154. 

Otospermophilus grammurus, 154. 

Spermophilus beecheyi, 154. 

Spermophilus grammurus, 154. 
Flying squirrel, 35, 52. 
Fossil species, 214. 
Fox squirrel, 34, 50. 
franklini, Spermophilus, 133. 
franklinii, Arctomys, 42, 133. 

Citellus, 3, 5, 21 (habits), 41, 42, 
43, 44, 133, 215. 

Colobotis, 54. 

Poliocitellus, 43, 44. 

Spermophilus, 133. 
frater, Eutamias quadrivittatus, 48. 



1938] 



REVISION OF THE GROUND SQUIRRELS 



251 



fulvus, Citellus, 54. 

Spermophilus, 53, 54. 

Geographic distribution, 2. 

gerrardi, Sciurus, 51. 

gidleyi, Otospermophilus, 215. 

Glaucomys, 35, 52. 

goldmani, Citellus annulatus, 164. 

Otospermophilus annulatus, 164. 

Sciurus, 49. 

Spermophilus annulatus, 164. 
grammurus, Anisonyx, 142. 

Citellus, 43, 45, 55. 

Citellus grammurus, 142. 

Citellus variegatus, 23, 43, 137, 139, 
140, 141, 142, 146, 147, 148. 

Otospermophilus, 142. 

Otospermophilus grammurus, 142. 

Sciurus, 43, 53, 142. 

Spermophilus grammurus, 142. 
Gray gopher, 21. 
Gray squirrel, eastern, 34. 

western, 34. 
griseoflavus, Sciurus, 49. 
griseus, Sciurus, 49, 50. 
Ground hog, 37. 
Ground squirrel, Aleutian, 98. 

antelope, 5, 29 (habits), 54. 

Apache spotted, 125. 

Arizona mantled, 196. 

Arizona round-tailed, 187. 

Arizona striped, 116. 

Barrow, 95. 

Belding's, 11 (habits), 81. 

Bennett's spotted, 122. 

Bighorn striped, 114. 

Blue Mountains, 89. 

Blue Mountains mantled, 205. 

California, 4, 5, 23 (habits), 148. 

Gary's mantled, 197. 

Cascade mantled, 212. 

Catalina, 160. 

Catavina, 159. 

Charleston Mountains mantled, 
208. 

Columbian, 4, 5, 13 (habits), 55, 
85. 

desert spotted, 130. 

Douglas's, 5, 27 (habits), 150. 

Fisher's, 154. 

Franklin's, 5, 21 (habits), 39, 55, 
133. 

golden-mantled, 203. 

Goldman's, 28 (habits), 164. 

gray, 3, 67. 

Hoilister's mantled, 199. 

HoUister's striped, 115. 

Idaho spotted, 72. 

Jaurez, 158. 

Kennicott's spotted, 130. 

Kodiak, 103. 

least Idaho, 65. 

least striped, 117. 

lesser California, 156. 

lesser tropical, 29 (habits), 165. 



Ground squirrel — -Continued. 

Loring's, 71. 

Malheur Vallev, 66. 

mantled, 5, 31 (habits), 35, 39, 54. 

Merriam's mantled, 198. 

Mexican, 20 (habits), 119. 

Mexican spotted, 55. 

Mohave, 30 (habits), 183. 

Nevada, 77. 

Nevada mantled, 206. 

New Mexico spotted, 126. 

Oregon, 4, 5, 12 (habits), 83. 

Padre Island, 128. 

pallid spotted, 124. 

pallid striped, 112. 

Palm Springs, 188. 

park spotted, 128. 

Parrv's, 16 (habits), 88, 91. 

Perote, 21, 132. 

Piute, 63. 

Richardson's, 4, 5, 8 (habits), 55, 
73. 

ring-tailed, 28 (habits), 39, 163. 

Rio Grande. 121. 

round-tailed, 5, 30 (habits), 185. 

St. Lawrence Island, 101. 

San Bernardino mantled, 209. 

sandhill striped, 111. 

Say's mantled, 191. 

Shumagin, 100. 

Sierra, 153. 

Sierra Madre mantled, 213. 

Snake Vallev, 6 (habits), 68. 

spotted, 5, 20 (halnts), 39. 

striped, 5, 18 (habits), 39, 55. 

Texas striped. 110. 

thirteen-lined, 107. 

Townsend's, 5 (habits), 60. 

Trinidad Valley, 190. 

Trinitv Mountains mantled, 211. 

Uinta,' 4, 10 (habits), 78. 

Wasatch mantled, 201. 

Washington, 5, 7 (habits), 69. 

Wortman's mantled, 195. 

Wvoming, 5, 10 (habits), 76. 

Yolla Bolly mantled, 210. 

Yukon, 97. 

Yukon Valley, 17 (habits), 104. 

See also Antelope squirrel, Rock 
squirrel. 
Gucrlinguetus, 50. 
guerlinguetus, Sciurus, 50. 
gunnisoni, Cynomys, 55, 88. 

Spermophilus, 38. 
guttatus, Citellus, 71. 

Spermophilus, 62. 

Habits and economic relations, 4. 
harrisi, Citellus, 167. 

Tamias, 167, 170. 
harrisii, Ammospermophilus, 167. 

Anisonyx, 167. 

Citellus harrisii, 167, 170, 171, 172. 

Spermophilus, 55, 56, 167, 170. 
Hesperosciurus, 34, 49. 



252 



NORTH AMERICAN FAUNA 



[No. 56 



hoffmanni, Sciurus, 51. 

hoUisteri, Citellus tridecemlineatus, 115, 

117. 
hoodii, Arctomys, 55, 107. 

Colobotis, 54. 
hudsonicus, Sciurus, 51. 

Tamiasciurus, 50. 
hypopyrrhus, Sciurus aureogaster, 48, 49. 

Ictidomoides, 41, 53, 54. 
Ictidomys, 39, 41, 42, 53, 54, 106, 215, 
216. 

badius, 110. 

mexicanus, 43. 

tereticaudus, 187. 
idahoensis, Citellus, 6 (habits), 54, 63, 

68, 69, 72. 
insularis, Ammospermophilus leucurus, 
181. 

Citellus, 164, 181. 

Citellus leucurus, 181. 
nterpres, Ammospermophilus, 180. 

Ammospermophilus leucurus, 180. 

Citellus, 169, 176, 180. 

Spermophilus, 180. 

Tamias, 180. 
isthmius, Microsciurus, 51. 

juglans, Citellus variegatus, 142, 144. 

kadiacensis, Citellus parry i, 103. 
kaibabensis, Sciurus, 50. 
kennicotti, Citellus parryi, 91. 

Colobotis parryi, 91. 
kennicottii, Arctomys, 55, 91, 94. 

Citellus parryi, 91. 
Keys — 

Ammospermophilus, 167. 

Callospermophilus, 191. 

Citellus, 56, 59. 

Ictidomys, 106. 

Notocitellus, 162. 

Otospermophilus, 135. 

Sciuridae, 36. 

Xerospermophilus, 183. 
kinoensis, Ammospermophilus harrisii, 

169. 
kodiacensis, Citellus, 97, 99, 100, 103. 

Spermophilus empetra, 103. 

Spermophilus parryi, 103. 

Spermophilus parryii, 56. 

lateralis, Arctomys, 191. 

Callospermophilus, 43, 192. 

Citellus, 43, 55, 192. 

Citellus laterahs, 191, 195, 196, 197, 
198, 201, 202, 203, 212, 213, 214. 

Sciurus, 45, 53, 191. 

Spermophilus, 56, 191. 

Tamias, 192. 
Leucocrossuromys, 38. 
leucurus, Ammospermophilus, 170. 

Citellus leucurus, 168, 169, 170, 
173, 174, 175, 176, 177, 178, 179, 
180, 182. 

Spermophilus, 53, 54, 170. 

Tamias, 44, 170. 
leurodon, Citellus, 63, 64. 



loringi, Citellus Washington!, 71. 

ludovicianus, Cynomys, 38. 
lyratus, Citellus, 101. 

Citellus parryii, 97, 99, 101, 103. 

macrospilotus, Anisonyx spilosoina, 125. 

Citellus spilosoma, 125. 

Spermophilus spilosoma, 125. 

Xerospermophilus spilosoma, 125. 
macrourus, Spermophilus, 55, 136. 
madrensis, Callospermophilus, 213. 

Citellus, 46, 191, 213. 
major, Citellus spilosoma, 126, 128, 129, 
130, 131. 

Spermophilus spilosoma, 126. 
managuensis, Sciurus, 49. 
marginatus, Spermophilus spilosoma,12Gf 

127. 
Marmot, 35, 36, 37, 38. 

Marmota, 35, 37, 38, 53. 

marmota, 38. 

monax, 38. 
marmota, Marmota, 38. 

Mus, 37. 
Marmotops, 38. 
merriami, Tamias asiaticus, 47. 
Mesosciurus, 50. 

mexicanus, Citellus, 5, 20, 41, 42, 43, 54. 
215, 216. 

Citellus mexicanus, 119, 121, 122. 

Citillus, 119. 

Ictidomys, 43. 

Otospermophilus, 119. 

Sciurus, 41, 53, 119. 

Spermophilus, 119. 
Microsciurus, 35, 51, 52. 

alfari, 51. 

boquetensis, 51. 

isthmius, 51. 

septentrionalis, 51. 
microspilotus , Citellus spilosoma, 125. 

Spermophilus spilosoma, 125. 
mitratus, Callospermophilus chryso- 
deirus, 210. 

Citellus lateralis, 204, 210, 212. 
mohavensis, Citellus, 30 (habits), 183, 
185, 186. 

Citellus tereticaudus, 183, 185. 

Spermophilus, 45, 53, 54, 183. 
mollis, Citellus, 5. 

Citellus townsendii, 6, 7, 45, 54, 63, 
65, 66, 67, 68, 72, 106, 183, 184, 
185, 186. 

Spermophilus, 55, 62, 63. 

Spermophilus townsendi, 63. 
monax, Marmota, 38. 
monticola, Citellus tridecemlineatus, 

116, 118. 
Mus citellus, 39, 40, 53. 

citillus, 53. 

empetra, 91. 

marmota, 37. 

volans, 52. 

nayaritensis, Sciurus, 50. 
nebulicola, Citellus, 100. 

Citellus parryii, 100, 102. 



19381 



REVISION OF THE GROUND SQUIRRELS 



253 



neglectus, Citellus, 187. 

Citellus tereticaudus, 186, 187. 

Spermophilus, 187. 
nelsoni, Ammospermophilus, 182. 

CiteUus, 182. 

Sciurus, 49. 

Spermophilus, 182. 
Neosciurus, 34, 48, 50. 

carolinensis, 51. 
Neotamias, 47. 
nesioticus, Citellus, 160. 

Citellus beecheyi, 160. 

Otospermophilus, 160. 
nevadensis, CiteUus elegans, 77. 

CiteUus richardsonii, 77, 79. 
niger, Sciurus, 50. 
Notocitellus, 39, 44, 45, 162. 

annulatus, 46. 
nudipes, Citellus beecheyi, 150, 157, 
158, 160. 

obsidianus, Spermophilus spilosoma, 128. 
obsoletus, Citellus, 130. 

CiteUus spnosoma,127, 130. 

Spermophilus, 55, 130. 
oculatus, Sciurus, 50. 
olivaceus, Spermophilus tridecemlineatus, 

112, 113. 
oregoDUS, Citellus, 83. 

Citellus beldingi, 5, 12 (habits), 
41, 43, 77, 79, 80, 82, 83. 

Spermophilus, 83. 
osgoodi, CiteUus, 17 (habits), 54, 92, 
98, 104. 

Spermophilus, 104. 
Otocolobus, 53. 
Otosciurus, 34, 50. 

Otospermophilus, 5, 35, 39, 42, 43, 45, 
48, 53, 135, 164, 215. 

adocetus, 165. 

annulatus, 163. 

atricapiUus, 161. 

beecheyi, 44, 148. 

buckleyi, 141. 

couchii, 140. 

douglasii, 151. 

fisheri, 154. 

gidleyi, 215. 

goldmani, 164. 

grammurus, 142. 

mexicanus, 119. 

nesioticus, 160. 

rupestris, 138. 

tularosae, 145. 

Utah, 146. 

variegatus, 136. 

pallescens, CiteUus spilosoma, 124, 125, 

126, 132. 
pallidus, CiteUus tridecemlineatus, 109, 
111, 112, 115, 118. 

Spermophilus tridecemlineatus, 56, 
112. 
Parasciurus, 34, 50, 51. 
parryi, Arclomys, 88. 
Citellus, 91. 
Colobotis, 91. 
Spermophilus, 91. 



parryii, Arctomys, 91, 

Citellus, 3, 38, 39, 54, 55, 90, 136. 

CiteUus parryii, 16 (habits), 91, 
95, 96, 97, 98, 99, 100, 104, 105. 

Spermophilus, 91. 
parvidens, Citellus mexicanus, 119, 121. 

Spermophilus mexicanus, 121. 
parvulus, Citellus beecheyi, 150, 155, 

156, 158, 159, 160. 
parvus, CiteUus tridecemlineatus, 113, 
115, 117. 

Citellus tridecimlineatus, 117. 

Spermophilus tridecemlineatus, 117. 
peninsulae, Ammospermophilus leucu- 
rus, 176. 

Citellus leucurus, 166, 176, 178, 179. 

Tamias leucurus, 176. 
pennipes, Ammospernaophilus leucurus, 
175. 

Citellus leucurus, 175. 
perotensis, CiteUus, 21, 41, 42, 132. 

Spermophilus, 132. 
perpallidus, Callospermophilus chryso- 

deirus, 206, 207. 
pessimus, Citellus mollus, 65. 
phaeognatha, Arctomys, 55. 

Arctomys parryi, 91. 
Plague, bubonic, 10, 11, 13, 16, 26. 
plesius, CiteUus, 97. 

Citellus parryii, 16, 17, 86, 87, 88, 
92, 97, 99, 100, 105, 133. 

Spermophilus, 17, 18. 

Spermophilus empetra, 97. 
Pocket gopher, 11. 
Poliocitellus, 39, 42, 133. 

franklinii, 43, 44. 
poliopus, Sciurus, 49. 
Prairie dog, 35, 36, 38, 55, 88. 
pratensis, Citellus spilosoma, 128, 130. 

Spermophilus spilosoma, 128. 
Protospermophilus quatalensis, 214, 215. 
Pygmy squirrel, 51, 52. 

quatalensis, Citellus, 214, 215. 
Protospermophilus, 214, 215. 

Red squirrel, 51. 
richardsoni, Citellus, 73. 

Spermophilus, 62. 
richardsonii, Arctomys, 73. 

CiteUus, 54, 85. 

Citellus richardsonii, 5, 8 (habits') 
73, 76, 77, 78, 79, 81, 86. 

Colobotis, 54. 

Spermophilus, 56, 73. 
richmondi, Sciurus, 51. 
ridgwayi, Citellus, 215. 
Rock squirrel, 5, 22 (habits), 35, 39, 43, 
53. 

black-backed, 141. 

brown-headed, 138. 

Couch's, 139. 

Lower California, 161. 

Malpais, 145. 

Mexican, 55, 136. 

Say's, 23, 142. 

Utah, 4, 146. 

See also Antelope squirrel, Ground 
squirrel. 



254 



NORTH AMERICAN FAUNA 



[No. 66 



Rocky Mountain spotted fever, 16. 
ruficaudus, Citellus columbianus, 88, 89. 
rupestris, Citellus grammurus, 138. 

Citellus variegatus, 137, 138, 140, 
141, 144. 

Otospermophilus grammurus, 138. 
rupinarum, Citellus beecheyi, 159. 

saturatus, Callospermophilus lateralis, 
212. 

Citellus, 191, 203, 212. 

Citellus lateralis, 212. 

Spermophilus lateralis, 212, 

Tamias lateralis, 212. 
saxicola, Ammospermophilus harrisii, 169. 

Citellus harrisi, 169. 

Citellus harrisii, 169. 

Spermophilus harrisi, 169. 
saxicolus, Spermophilus harrisii, 169. 
Sciuridae, classification, 34. 
Sciurus, 34, 35, 48. 

aberti, 49, 50. 

adolphei, 49. 

aestuans, 50. 

alfari, 51. 

alleni, 50. 

apache, 50. 

arizonensis, 50. 

asiaticus, 47. 

aureogaster, 49. 

boothiae, 49. 

buccaius, 136. 

carolinensis, 48, 49, 50, 51, 

coUiaei, 49. 

concolor, 50. 

deppei, 49. 

durangi, 50, 

gerrardi, 51. 

goldmani, 49. 

grammurus, 43, 53, 142. 

griseoiiavus, 49, 

griseus, 49, 50. 

guerlinguetus, 50. 

hoffmanni, 51. 

hudsonicus, 51. 

hypopyrrhus, 48, 49. 

kaibabensis, 50, 

lateralis, 45, 53, 191. 

managuensis, 49, 

mexicanus, 41, 53, 119. 

nayaritensis, 50. 

nelsoni, 49. 

niger, 50. 

oculatus, 50. 

poliopus, 49. 

richmondi, 51. 

sinaloensis, 49. 

socialis, 49, 

striatus, 46. 

thomasi, 49. 

tridecemlineatus, 41, 53, 55, 107. 

truei, 49, 

variegatoides, 49. 

variegatus, 136, 137. 

vulgaris, 48, 49, 50. 

yucatanensis, 49. 
septentrionalis, Microsciurus, 51. 
Seton, Ernest Thompson, 2. 



sierrae, Citellus beecheyi, 153, 155. 
sinaloensis, Sciurus, 49. 
socialis, Cynomys, 38. 

Sciurus, 49. 
sonomae, Eutamias townsendii, 48. 
sonoriensis, Spermophilus, 187, 188. 
Spermatophilus, 53. 
Spermophila,- 53. 
Spermophiie, eared, 43. 

Parry's, 55, 56. 

round-tailed, 55. 
Spermophilis, 53. 
Spermophillus, 53. 
Spermophilus, 53. 

alleni, 114. 

annectens, 128. 

annulatus, 44, 55, 16b. 

arens, 125. 

armatus, 55, 56, 78. 

atricapillus, 161. 

hadius, 110, 111, 

harrowensis, 95, 

beecheyi, 148. 

beldingi, 56, 81. 

beringensi$, 95. 

bernardinus, 209, 

brevicaudus, 209. 

buckleyi, 55, 141, 

canescens, 125, 

canus, 67, 

castanurus, 201. 

chrysodeirus, 203. 

cinerascens, 198. 

cinnamomeus, 174. 

columbianus, 85. 

concha, 55, 139. 

cryptospilotus, 130, 

douglasii, 150, 

douglassi, 150. 

elegans, 55, 56, 62, 76. 

em,petra, 56, 91. 

erythroglutaeus, 85, 

erythrogluteia. 85, 

eversmanni, 53. 

fisheri, 154, 

franklini, 133. 

franklinii, 133. 

fulvus, 53, 54. 

goldmani, 164. 

grammurus, 142. 

gunnisoniy 38. 

guttatus, 62. 

harrisii, 55, 56, 167, 170. 

interpres, 180. 

kodiacensis, 56, 103. 

lateralis, 56, 191. 

leucurus, 53, 54, 170. 

macrospilotus, 125. 

macrourus, 55, 136. 

major, 126, 

marginatus, 126, 127. 

mexicanus, 119. 

microspilotus, 125. 

mohavensis, 45, 53, 54, 183. 

mollis, 55, 62, 63, 

neglectus, 187. 

nelsoni, 182, 

obsidianus, 128, 



1938] 



REVISION OF THE GROUND SQUIRRELS 



255 



Spermophilus — Continued. 

obsoletus, 55, 130. 

olivaceus, 112, 113. 

oregonus, 83. 

osgoodi, 104. 

pallidus, 56, 112. 

parryi, 91. 

parryii, 91. 

parvidens, 121. 

parvus, 117. 

peroiensis, 132. 

plesius, 17, 18, 97. 

pratensis, 128. 

richardsoni, 62. 

richardsonii, 56, 73. 

saturatus, 212. 

saxicola, 169. 

saxicolus, 169. 

sonoriensis, 187, 188. 

spilosomd, 122. 

stephensi, 63, 64. 

tereticaudus, 55, 185. 

texensis, 110. 

townsendi, 65, 76. 

fownsendii, 56, 60, 69, 76. 

tridecemlineatus, 107. 

variegatus, 136. 

wortmani, 195. 

yakimensis, 60. 
spilosoma, Citellus, 5, 20 (habits), 31, 
41, 42, 55, 70, 120. 

Citellus spilosoma, 122, 124, 126, 
131, 132. 

Spermophilus, 122. 
Squirrel, Abert's, 34. 

flying, 35, 52. 

fox, 34, 50. 

gray, 34. 

pygmy, 51, 52. 

red, 51. 

tree, 34, 35, 36, 39, 42, 48, 164. 

(See aZso Antelope squirrel. Ground 
squirrel, Rock squirrel, 
stejnegeri, Citellus, 3. 
stephensi, Spermophilus mollis, 63, 64. 
stonei, Citellus, 98, 100. 
striatus, Tamias, 46. 

Sciurus, 46. 
Syntheosciurus, 35, 52. 

brochus, 52. 

Tamias, 35, 46, 47, 56. 

chrysodeirus, 203. 

castanurus, 201. 

cinerascens, 198. 

cinnamomeus, 174. 

harrisi, 167, 170. 

inierpres, 180. 

lateralis, 192. 

leucurus, 44, 170. 

merriami, 47. 

peninsulae, 176. 

saturatus, 212. 

striatus, 46. 

wortmani, 195. 
Tamiasciurus, 34, 35, 51. 

hudsonicus, 50. 
taylori, Citellus, 216. 



tereticaudus, Anisonyx, 187. 

Citellus, 30 (habits), 41, 45, 184. 
Citellus tereticaudus, 185, 187, 

189, 190. 
Ictidomys, 187. 
Spermophilus, 55, 185. 
tersus, Ammospermophilus leucurus, 
173. 

Citellus leucurus, 173. 
tescorum, Callospermophilus lateralis, 
199. 

Citellus lateralis, 198, 199, 206, 
212, 213. 
texensis, CiteUus tridecemlineatus, 107, 
109,110,111,122. 
Spermophilus tridecemlineatus, 110. 
thomasi, Sciurus, 49. 
Thomomys, 11. 
Thompson, Ernest E., 2. 
townsendi, Citellus, 216. 
Spermophilus, 65. 
Spermophilus richardsoni, 76. 
townsendii, Citellus, 5 (habits), 55, 69, 
73. 

Citellus to^\Tisendii, 5, 60, 70, 71. 
Spermophilus, 56, 60, 69, 76. 
trepidus, Callospermophilus, 206. 
CiteUus, 206. 

CiteUus lateraUs, 201, 202, 204, 
206, 208. 
tridecemlineata, Arctomys, 107. 
tridecemlineatus, Citellus, 3, 5, 18 
(habits), 21, 31, 41, 42, 54, 106, 118, 
216. 

Citellus tridecemlineatus, 107, 110, 

113, 115, 119. 
Colobotis, 54. 
Sciurus, 41, 53, 55, 107. 
Spermophilus, 107. 
tridecimlineatus, Citellus, 107. 
trinitatis, Callospermophilus chryso- 
deirus, 211. 

Citellus chrysodeirus, 211. 
Citellus lateralis, 210, 211. 
truei, Sciurus, 49. 
tuitus, CiteUus, 215. 
Tularemia, 6, 26, 27. 
tularosae, Citellus grammurus, 145. 
Citellus variegatus, 145. 
Otospermophilus grammurus, 145. 
Type localities, list of, 56. 

Urocitellus, 53. 

Utah, Citellus grammurus, 146. 

Citellus variegatus, 144, 146. 

Otospermophilus grammurus, 146. 

variegatoides, Sciurus, 49. 
variegatus, CiteUus, 22 (habits), 54, 55, 
136. 

CiteUus variegatus, 22, 136, 138, 
140, 146. 

Otospermophilus, 136. 

Sciurus, 136, 137. 

Spermophilus, 136. 
vigilis, Citellus canus, 66. 

Citellus mollis, 66. 

CiteUus townsendii, 61, 66, 67, 68. 



256 



NORTH AMERICAN FAUNA 



vinnulus, Citellus leucurus, 170. 
vociferans, Citellus tereiicaudus, 185, 186. 
volans, Mus, 52, 
vulgaris, Sciurus, 48, 49, 50. 

Washington!, Citellus, 5, 6, 7, (habits), 
54, 62, 73, 216. 

Citellus Washington!, 63, 69, 71, 72, 
106, 107. 
washoensis, Citellus mollis, 63, 64. 
Woodchuck, 37. 
wortmani, CaUospermophilus, 195. 

Callospermophilus lateralis, 195. 

CiteUus, 195. 

CiteUus lateralis, 191, 193, 195. 



wortmani — Continued. 
Spermophilus, 195. 
Tamias, 195. 

Xerospermophilus, 5, 39, 45, 53, 54, 183, 

184. 

canescens, 125. 
cryptospilotiis, 130. 
macrospilotus, 125. 

yakimensis, Citellus mollis, 60, 63. 

Spermophilus mollis, 60. 
yucatanensis, Sciurus, 49. 

Ziesel, 53. 



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UNITED STATES DEPARTMENT OF THE INTERIOR 
'Harold L. Ickes, Secretary 

FISH AND WILDLIFE SERVICE 
Ira N. Gabrielson, Director 



North American Fauna 57 



ATTWATER'S PRAIRIE CHICKEN 

ITS LIFE HISTORY AND 

MANAGEMENT 



BY 

VALGENE W. LEHMANN 




UNITED STATES 

GOVERNMENT PRINTING OFFICE 

WASHINGTON : 1941 



For sale by the Superintendent of Documents, Washington, D. C. - - • - Price 40 cents 



i ir' 



ABSTRACT 

ATTWATER'S PRAIRIE CHICKEN, a characteristic bird of the Texas 
coastal prairie, is closely related to the now extinct heath-hen of 
northeastern North America. Once abundant in an area extending from the 
coastal tall -grass prairies of southwestern Louisiana and Texas west and south 
to near Port Isabel, it has decreased in numbers as man has exploited its 
habitat, until now it is threatened ^vith the same fate as that of the heath-hen. 

Important factors limiting the numbers of the bird include excessive or 
persistent rainfall dm-ing the nesting season, heavy grazing, excessive pasture 
burning, agricultvu^al operations, and overshooting. Management will 
usually involve protection from excessive kiUing, improvement of food and 
cover, and control of predators and of the kill by hunters. Responsibility 
for this rests with the landowTier. 

Optimum prairie chicken range apparently consists of well-drained grass- 
land, with some weeds or shrubs, the cover varying in density from light to 
heavy; and with surface water available in summer; diversification within 
the grassland type is essential. In the absence of ample refuges for the 
species, probably all other favorable factors together will fail to save 
Attwater's prairie chicken from extinction. 

This number continues the series of the North American Fauna issued by 
the Bureau of Biological Survey, of the United States Department of Agri- 
culture, prior to its transfer and consolidation with the Bureau of Fisheries 
on June 30, 1940, to form the Fish and Wildlife Service, in the Department 
of the Interior. 



CONTENTS 

Page 

Introduction 1 

Former distribution of prairie chickens in Texas 2 

Differences between Attwater's and the other prairie chickens 4 

Attwater's prairie chicken 4 

Lesser prairie chicken 5 

Former abundance of Attwater's prairie chickens 6 

Present distribution and numbers 7 

Habits 10 

Courtship and mating 10 

Nesting 14 

Growth and development of young 16 

Brood size 18 

Juvenile mortality 19 

Family disintegration 19 

Annual increase 20 

Flocking 20 

Seasonal movements 21 

Spring 21 

Summer 22 

Fall and winter 24 

Food 25 

Habitat requirements 30 

Kind of environment best suited 30 

Character and density of vegetation 30 

Topography 30 

Water 31 

Seasons of scarcity 31 

Limiting factors 31 

Natural factors 32 

Rainfall during the nesting season _■ 32 

Floods 35 

Drought 35 

Hurricanes 35 

Hail 35 

Local storms 36 

Disease 36 

Spread of woody vegetation 36 

Predation 37 

Nests 37 

Young 38 

Adults 39 

Review of natural factors 40 

Artificial factors 40 

Agriculture 40 

Pasture burning 41 

rn 



IV CONTENTS 

Limiting factors — Continued. 

Artificial factors— Continued. Page 

Overgrazing 42 

Oil development 43 

Drainage 43 

Pasture mowing _ 43 

Mechanical accidents 44 

Hunting 44 

Management 45 

Protection 45 

Habitat improvement 46 

Evaluating conditions 47 

Census methods 47 

Spring counts on the courtship grounds 47 

Rope count 49 

Car-dog count 52 

Using the census 52 

Spring 53 

Summer 54 

Winter 55 

General recommendations for habitat control 56 

Predator control 57 

Harvesting the surplus 57 

Restocking 58 

Summary 59 

Literature cited 62 

Index 65 



ILLUSTRATIONS 



Plate Facing page 

1. Attwater's prairie chickens (Tympanuchus cupido attwateri) on boom- 

ing ground Frontispiece 

2. Dense cordgrass areas in Aransas County, Tex 4 

3. Male Attwater's prairie chicken, showing vocal sacs 10 

4. Nest and eggs of Attwater's prairie chicken; Colorado County, Tex__ 14 

5. Concealment of nests by Attwater's prairie chicken; Colorado County, 

Tex 15 

6. Chicks of Attwater's prairie chicken; Colorado County, Tex 16 

7. Wild indigo (Baptisia) in a closely grazed pasture; Austin County, 

Tex 22 

8. Diversified cover — excellent prairie chicken range; Colorado County, 

Tex 30 

9. Medium-heavy to heavy cover — excellent food-cover conditions in a 

moderately grazed pasture; Colorado County, Tex 31 

10. Shells of eggs at prairie chicken nest destroyed by house cat; Colorado 

County, Tex 38 

11. Native bluestem prairie — well populated by prairie chickens; Colorado 

County, Tex 39 

12. Excellent unburned cover at right of road; inferior burned cover at 

left; Colorado County, Tex 42 

13. Rope counting of prairie chickens on Matagorda Island, Tex 48 

14. Fenced plot planted to hegari; Wharton Countj', Tex 56 

Figure Page 

1. Distribution of Attwater's prairie chickens in Texas 3 

2. Movements of a combined brood, Colorado County, Tex 23 

3. Rainfall conditions in May in the range of Attwater's prairie chicken in 

Texas Facing page 34 

4. Diagram of the rope count 50 

V 



ATTWATER'S PRAIRIE CHICKEN 

By Valgene W. Lehmann 
Collaborator, Division of Wildlife Research, Fish and Wildlife Service^ 



INTRODUCTION 

Attwater's prairie chicken {Tympanuchu-s cupido aUwateri Ben- 
dire) (see frontispiece), might well be called the heath-hen of the 
South. It is so closely related to the now extinct heath-hen {T. c. 
cupido) of northeastern North America as to be classified in the 
same species. Like the heath-hen, Attwater's prairie chicken once 
-inhabited a large area, its former range including the coastal tall- 
grass (Andropogon) prairies of southwestern Louisiana and in Texas 
west and south to Cameron County, near Port Isabel. In certain 
areas the birds were abundant. Old-timers report that the deep 
booming courtship calls of the males once reverberated from the 
prairies with such force and monotony as actually to pain sensitive 
eardrums. The bird, however, is no longer abundant. It has de- 
creased in numbers as man has exploited its habitat until now it is 
threatened with the fate of the heath-hen — extinction. 

In his "Biological Survey of Texas" Vernon Bailey (1905: 19)' 
places Attwater's prairie chicken at the head of the list of breeding 
birds of the Texas coastal prairie. In addition to being a character- 
istic bird of the region, this prairie chicken is probably the most 
popular species wherever found. Most people who know it have a 
genuine appreciation of its color and charm. Rare indeed is the 
person who finds no esthetic stimulus in the sight of a strutting 
male on the booming ground, or a brood of downy chicks on the edge 
of a short-grass flat. Both ranchmen and farmers highly appreciate 
the prairie cliicken's appetite for grasshoppers, salt-marsh cater- 
pillars {Estigmene dcraea)^ and the moths of the cotton leaf worm 
{Alabama argillacea). Under proper conditions prairie chicken 
hunting provides a high type of sport, and the flesh of the birds, 
especially that of the young, is highly esteemed as food. 



1 Cooperative contribution from the Texas Cooperative Wildlife Research Unit, estab- 
lished by the Agricultural and Mechanical College of Texas ; the Texas Game, Fish, and 
Oyster Commission ; the American Wildlife Institute ; and the Fish and Wildlife Service. 

* Publications referred to parenthetically by date (alone or followed by colon and specific 
page) are listed in the Literature Cited, p. 62. 



Explanation of Fkontispiece 

Attwater's prairie chicl^ens (Tympanuchus cupido 
attwateri) on booming ground 



2 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

The real appeal of the prairie chicken, however, lies in its con- 
nection with the colorful and eventful early days in Texas. The 
prairie hen summons memories ; it prompts old-timers to recall when 
the range was free of wire fences and oil derricks, and rich grasses 
grew waist high. Thoughtful people deplore the passing of Att- 
water's prairie chicken, one of the last landmarks of the prairie as 
it used to be. Highly appropriate was the selection of this bird as 
a species of major interest by the Texas Cooperative Wildlife Re- 
search unit.' 

FORMER DISTRIBUTION OF PRAIRIE CHICKENS IN TEXAS 

H. C. Oberholser, in a letter to the present writer, states that in 
his opinion prairie chickens once occurred at some time of year on 
most prairie areas in Texas. In the main it appears that the differ- 
ent kinds of prairie chickens in the State occupied separate ranges, 
and that mixing and intergradation were confined largely to marginal 
areas. 

The principal former range of the greater prairie chicken in Texas, 
as indicated by the records of F. M. Bailey (1927: 130), Gross (Bent 
1932: 262), Strecker (1927: 321), and old residents with whom the 
writer has conferred, was northeastern Texas southwest to the vicin- 
ity of Waco. Likewise, records show that the lesser prairie chicken 
was indigenous to northwestern Texas and the high plains region 
in winter to about Bandera and westward through the "hill country" 
to the arid plains west of the Pecos River (Bendire 1892: 355, and 
others). Attwater's prairie chicken, it appears, was largely confined 
to the better-drained prairies of western Louisiana and Southeastern 
Texas (fig. 1, p. 3). 

According to Oberholser (1938: 190-191) the eastern limit of the 
range of Attwater's prairie chicken was in the vicinity of Abbeville, 



* So many persons have assisted in the prairie chicken studies that it is impossible to 
list them all. General supervision of the work was by Walter P. Taylor, leader of the 
Texas Cooperative Wildlife Research Unit, College Station, Tex. Valuable editorial 
suggestions were received from W. B. Davis, professor of wild game, School of Agriculture, 
Agricultural and Mechanical College of Texas ; and from William J. Tucker, executive 
secretary, Texas Game, Fish, and Oyster Commission. The bulk of examinations of crops, 
gizzards, and scats was done by Clarence Cottam, Clarence F. Smith, and their associates 
in the Section of Food Habits, Division of Wildlife Research, Fish and Wildlife Service. 

In his field work in 1938 the writer was assisted by H. R. Siegler, field biologist of the 
Research Unit. Many Colorado County landowners cooperated ; among these, M. C. 
Shindler, Emil Gleuck, Ed Koy, Adolf Renz, and I. V. Duncan deserve special mention. 
E. P. Haddon, photographer of the Texas Commission, took some of the photographs here 
reproduced. The assistance of the State game wardens was indispensable. Deserving 
of special mention are T. S. Boothe, Beaumont ; J. C. Gardner, Hull ; R. Z. Cowart, Rosen- 
berg ; Ed McCloskey, Victoria ; C. D. Tidwell, Bay City ; G. P. Ferguson, Sinton ; and 
T. T. Waddell, Eagle Lake. Waddell's contributions to the study were outstanding; he 
gave most generously of his time, records, and extensive experience. To him, and to all 
others, the writer is deeply grateful. 



ATTWATER'S PRAIRIE CHICKEN 3 

Opelousas, and Bayou Teche in Louisiana. There are no authentic 
records of the occurrence of any species of prairie chicken in Texas 
south of northern Aransas County, except for one bird reported 
from near Brownsville by Merrill (1879: 159-160). Prairie chickens 
did not occur near San Antonio, Tex., in 1890, for Babbitt, in Bendire 
(1894: 130) wrote as follows: "The prairie hen is not found in the 




Probable Former Ranqe. 
Preacnf Range 



FiGiTBE 1. — Present tlistribution of Attwater's prairie chicken in Texas and 
probable former range in the coastal section. 

immediate vicinity of San Antonio, Tex., but exists in great numbers 
south and southeast from here, all at an average distance of 100 
miles. * * *" Simmons (1925: 82) submits the records of O. 
Brinkman and C. D. Oldright as evidence that Attwater's prairie 
chicken occurred as a breeding bird in the vicinity of Austin. Travis 



4 NORTE AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

County, and in Williamson County as late as 1878, but the accuracy 
of the data is questionable. Apparently the limit was the northern 
edge of the coastal prairie, 

Eoughly, the territory occupied by Attwater's prairie chicken was 
south of a line extending northeast from Kefugio tlirough Fannin, 
Thomaston, Provident City, Rock Island, Industry, Welcome, Bell- 
ville, Prairie View, Tom Ball, Humble, Liberty, Devers, Cheek, and 
Orange. All this area of approximately 8,500,000 acres in coastal 
Texas, however, was not occupied. Deciduous woodlands near rivers, 
as along the San Antonio, Guadalupe, Colorado, Brazos, and 
Trinity, were used only to a limited extent and only along the mar- 
gins. Prairie chickens did not occupy the pine forests in Harris 
County and to the east or the thick mesquite-acacia brush that oc- 
curred in considerable stands in Calhoim and other western counties 
as much as 100 years ago. Brackish and salt-water marshes in Or- 
ange, Jefferson, and Chambers, and less widely in other counties 
to the west, and extensive cordgrass {Spartina spartinae) flats (pi. 2) 
in Aransas County and elsewhere in low country bordering the Gulf, 
probably always were little used by chickens except to a limited 
extent in winter. There were, however, about 6,000,000 acres of 
bluestem prairie that probably supported many prairie chickens in 
favorable years. 

DIFFERENCES BETWEEN ATTWATER'S AND THE OTHER PRAIRIE 

CHICKENS 

During the nineteenth century three kinds of prairie chickens oc- 
curred in Texas: the greater prairie chicken {Tympanuchus cupido 
americanus Reichenbach), Attwater's prairie chicken {T. c. attwateri 
Bendire), and the lesser prairie chicken {T. pallidicinctus Ridg- 
way). Differences between the greater and Attwater's prairie chick- 
ens are slight; the lesser prairie chicken is somewhat better 
characterized. 

ATTWATER'S PRAIRIE CHICKEN 

Bendire (1894: 130) described Attwater's prairie chicken as — 

Smaller than T. americanus [greater prairie chicken], darker in color, more 
tawny above, usually with more pronounced chestnut on the neck ; smaller 
and more tawny light colored spots on the wing coverts, and much more 
scantily feathered tarsus, the latter never feathered down to the base of 
toes, even in front ; a broad posterior strip of bare skin being always ex]X)sed, 
even in winter, while in summer much of the greater part of the tarsus is 
naked. 

In weight Attwater's prairie chicken, however, is not perceptibly 
lighter than the greater prairie chicken. The average of 10 males 
(33.11 ounces, as shown in table 1, p. 5) exceeded by 2.11 ounces 
the average weight of the greater prairie chicken (31 ounces), as 



North American Fauna 57, Fish and Wildlife Service 



Plate 2 




c3 


•< 


a 


^ 










!C 


<u 






4-^ 


t/3 


03 


3 


-*J 


<; 


-tJ 


<*-c 


< 


o 


>> 


Oi 


jD 


01 




& 


t3 


a> 


CO 





o 




O 


c3 




Lh 


03 


bD 


CS 


■a 





ATTWATER'S PRAIRIE CHICKEN 



given by Gross (1930a: 40). The average weight of six females 
(25.7 ounces) was only 0.6 ounce less than that of the female greater 
prairie chicken (26.3 ounces), according to the same authority (loc. 
cit.). The weight of Attwater's prairie chickens, especially that of 
males, varies perceptibly from season to season ; three males obtained 
at the beginning of the courtship season were appreciably heavier 
(about 7.5 ounces) than those collected at other times. Darkness of 
color, tawniness above, and the amount of chestnut on the neck are 
other characters that vary greatly both seasonally and individually. 
Winter specimens are generally lighter in color than those collected 
in spring; they have comparatively little chestnut on necks and 
backs. The feathering on the tarsus also varies with the season ; the 
legs of specimens collected in winter are well feathered to the base 
of the toes. The style of barring on the back and rump, according 
to F. M. Bailey (1927: 130), is the same for both subspecies, that is, 
the bars are single, broad, and solid black. Altogether, physical 
differences between Attwater's and the greater prairie chicken are 
minor and insufficient to allow accurate field identification. In a 
series of skins, however, the smaller measurements of wing, tail, bill, 
and total length and the differences in general ruddiness and buffiness 
of the underparts are characteristic and serve to separate Attwater's 
prairie chicken as a subspecies. 

Table 1. — Weights of 16 AUwatefs prairie chickens 



County 


Date collected 


Weight 1 


County 


Date collected 


Weight I 


Grams 


Ounces 


Grams 


Ounces 


MALES 

Colorado 

Do 


Apr. 17, 1939 > 
Sept. 1,1937 3 
Sept. 4.1937 3 
Oct. 23,1937 
Nov. 3,1937 

Jan. 6, 1938 
Jan. 27,1938 
Feb. 14,1938 


1, 135. 20 
682. 00 
590. 07 
760. 20 
874. 00 

723. 69 
715. 24 
726.80 


40.03 
24.05 
20. SI 
26.81 
30.82 

25.18 
25.22 
25.63 


MALES 

Eefugio 

Do 

Colorado.. 

Austin__ 

Colorado..- 

FEMALES 

Refugio... 

Colorado 

Do 


Feb. 15,1938 

do 

Mar. 18, 1938 
Apr. 10, 1938* 
July 26,1938 

Feb. 15,1938 
Aug. 20,1938 
Aug. 23,1938 


1, 103. 70 
1, 125. 20 
1, 120. 45 
1, 077. 26 
921. 34 

785. 60 
722. 89 
708. 72 


38.92 
39 68 


Do 

Do 


39.51 
38 00 


Do 


32 50 


FEMALES 

Colorado 

Do 


27.70 
25 50 


Austin 


25.00 









• Average weights: Males, ! 
' Taken from hawk. 

' Immature bird. 

* Taken from poacher. 



3.94 gm. (33.11 oz.); females, 730.49 gm. (25. 70 oz.). 



LESSER PRAIRIE CHICKEN 



The lesser prairie chicken is somewhat smaller than either of its 
relatives. Verne E. Davison, in a letter, reports that 20 mature males 
from Oklahoma weighed 23.50 to 31.50 ounces and averaged 27.56 
ounces. Five hens weighed 23.75 to 27.50 ounces and averaged 
25.55 ounces. In other words, these male lesser prairie chickens were, 
on the average, 3.44 ounces lighter than the male greater prairie 
chickens (31 ounces) weighed by Gross (1930a: 40); these female 



6 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

lesser prairie chickens weighed 0.55 ounces less than the female 
greater prairie chickens that Gross obtained. According to Bailey 
(1927: 131), the general coloration of the lesser prairie chicken is 
paler than that of either the greater or Attwater's, and the color 
and arrangement of the bars on back and neck also differ. Whereas 
the bars are single, broad, and solid black in both the greater and 
Attwater's forms, they are treble, a broad brown bar enclosed by 
two narrow black ones, in the lesser species. 

FORMER ABUNDANCE OF ATTWATER'S PRAIRIE CHICKEN 

Accurate information as to the former abundance of Attwater's 
prairie chicken is difficult to obtain, although the data at hand 
record their numbers in certain areas. Many old cattlemen of the 
coastal prairie have told the writer that in early days the prairie 
chickens were relied upon to furnish fresh meat for the cattle camps. 
The task of killing 40 or 50 prairie chickens was menial, the cook of 
the outfit usually attending to it. 

In the Eagle Lake area, Colorado County, not more than 35 years 
ago, prairie chickens were shot as clay pigeons are today. On ap- 
pointed occasions parties of 10 to 20 or more men encamped in the 
sandhill country along the Bernard River and hunted the birds for 
periods varying from a few days to a week or more. At the end 
of each day the chickens killed, or their heads, were tallied. At the 
end of the encampment period the party having killed the smallest 
number paid the expenses of the outing. Waddell and others state 
that 10 or more piles of prairie chickens, each containing upwards 
of 100 birds, usually were left at the camp sites to rot or to be eaten 
by vultures. These encampments began about July 4 and continued 
through fall and winter. 

During the summer of 1893 or 1894, in Matagorda County, near 
Bay City, V. L. LeTulle reports that 71 Attwater's prairie chickens 
were shot in 2 hours; and that in 1895, at the site of the present town 
of Van Vleck, he and 3 friends killed 72 birds in an afternoon, and 
except for poor marksmanship would have bagged many more. 
Near Wharton, in Wharton County, in the fall of 1894 or 1895, 
LeTulle found 340 piled where hunters had camped. 

Mendell Burrell of the Ray Pipkin ranch (Big Hill country, 
Jefferson County) told the writer that as late as 1920 his domestic 
chickens were fed under the ranch house in winter to prevent prairie 
chickens from consuming the grain. In the same area it is said that 
flocks of from 150 to 200 Attwater's prairie chickens often alighted 
in the introduced chinaberry trees {Melia azedarach imibraculifera) 
around the ranch houses and fed extensively on the berries. In 
verification of this statement W. S. Boothe, State game warden at 



ATTWATER'S PRAIRIE CHICKEN 7 

Beaumont, Tex., presented the writer with a photograph, taken in 
1910 on the Wliite Ranch at Devers, showing a dozen prairie chickens 
in a chinaberry tree beside a house. 

C. H. Brosig, who hunted Attwater's prairie chickens in the Eagle 
Lake area for more than 40 years, reported that the birds once 
were so numerous in the sandhill country bordering the Bernard 
River that a new covey frequently was flushed while singles from 
one previously discovered were being pursued. Paul Mundelius noted 
a similar high density in concentrations of prairie chicken^ in the 
Sealy-San Felipe section in the eastern part of Austin County in 
1873-75. These conditions are seldom found on areas where the pop- 
ulation is less than one bird to an acre, and they show the former 
abundance of Attwater's prairie chickens in favorable areas. Not 
all the coastal bluestem {Andropogon) prairie, about 6,000,000 acres, 
wa3 equally favorable for prairie chickens even under pristine con- 
ditions; well-drained, well-populated country (one bird to an acre), 
as along the Bernard River, did not aggregate more than 900,000 
acres, or about 15 percent of the inhabited range. A little more than 
half, 3,300,000 acres, or 55 percent, of the prairie country was only 
fairly well drained ; these areas, protected for periods up to 17 years, 
now have a maximum population of about one bird to each 10 acres. 
Approximately 1,800,000 acres, or 30 percent, was poorly drained; 
prohibition of hunting for periods up to 15 years has not produced 
a population in excess of one bird to each 50 acres on certain of 
these large ranches. Probably, therefore, the former abundance of 
Attwater's prairie chicken in Texas approached, but seldom if ever 
attained or exceeded, 1,000,000 individuals, even in peak years. 

PRESENT DISTRIBUTION AND NUMBERS 

Data on the present status of Attwater's prairie chicken (table 2, 
p. 8) were obtained as follows: 

At least 90 percent of all fanns and ranches known or thought 
to have been occupied by the birds in 1937 were visited by the writer 
in company with local State game wardens. Unless the warden was 
thoroughly familiar with conditions on the various areas, conference^ 
were held with landowners, managers, cowboys, guides, hunters, or 
other persons who were in position to know the status of prairie 
chickens on particular tracts. After the conferences a general recon- 
naissance of the areas wa^ made by automobile or on horseback, and 
notes were taken on the topography, vegetation, surface water, and 
soil to ascertain the general suitability of the land for prairie chickens, 
as was done in similar studies previously made in the Eagle Lake area. 

Then in the light of all available information the range of Att- 
water's prairie chicken was mapped in each county, and representa- 



8 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

tive sample areag were selected for intensive study. The birds were 
then "rope counted" * on the sample tracts. Finally, the total popu- 
lation of the area was estimated from the data obtained by counting 
the sample plots. 



Table 2. — Population status of 


the Attwater's prairie cMckeri in Texas 


{1931) 




Size of 
tract 


Census area 


Territory occupied 
per bird 


Popula- 
tion of 
whole 
tract 


County 


Size 


Popula- 
tion (rope 
count) 


Census 
area 


Whole 
tract 




Acres 


Acres 
1,080 
630 


Number 
56 
106 


Acres 
19.2 
5.0 


Arre^ 


Numhtr 




















42,000 


1,610 


162 




9.9 


4,242 








6,554 
5,000 










3 25 


Goliad 1 










34 
















11, 554 
























Dewitt • 
















f 


230 
873 
218 


4 
14 



57.5 
62.3 






Victoria 












1 
















Total or average (3) 


65, 535 


1,321 


18 




73.4 


892 






Wharton i 


4,000 
4,915 
18, 022 
49,152 


























4,200 
14,250 


32 
315 


131.2 
45.2 




















76, 089 


18, 450 


347 




53.1 


1,433 


























736 























12, 288 
f 


736 









'50 












542 
364 
219 
157 
716 
482 


4 

1 
3 




135.5 








1 






Harris _ . 




219.0 
52.3 














I 






Waller .- -.- 








Fort Bend 




















Total or average (6) 


103, 878 


2,480 


8 




310.0 


335 








f 


585 
248 
269 
334 


29 
2 
1 
2 


20.1 
124,0 
269.0 
167.0 








.. . 




















I -" 






Galveston ' -__ 






















Total or average (7) 


54, 067 


1,436 


34 




42.2 


1,281 








Jefferson - 




4,000 
700 
400 


24 
1 



166.6 
700.0 






Ohamhers 








Liberty -- - 


















Total or average (8) 


91, 724 


5,100 


26 




204.0 


449 








Grand total or average 


457, 135 


31, 133 


594 




52.4 


8,711 







1 Counties in which prairie chickens occur but in which counts were not made because of scarcity of birds 
or similarity of the areas to adjoining counties. 

2 Numbers in parentheses in total lines refer to areas correspondingly numbered in the map, fig. 1, p. 3. 
' Estimates supplied by game wardens. 



* For an account of the method used in rope counting see p. 49. 



ATTWATER'S PRAIRIE CHICKEN 9 

The known range of Attwater's prairie chicken in Texas, as of 
September 1937, aggregated only 457,135 acres, as compared with 
approximately 6,000,000 acres in former times. The range has there- 
fore been reduced more than 93 percent during the past 100 years or so. 
The birds are still to be found in the counties of Aransas, Kefugio, 
Goliad, Victoria, Calhoun, Dewitt, Jefferson, Waller, Galveston, 
Chambers, Liberty, Lavaca, Wharton, Colorado, Matagorda, Austin, 
Fort Bend, Harris, Brazoria, and possibly Jackson and Orange, 
although they have not been reported by reliable observers in the 
last two for several years. They have definitely been extirpated 
from Willacy and Montgomery Counties, and their distribution has 
become restricted throughout the State, especially in the counties 
of Goliad, DeWitt, Lavaca, Calhoun, Matagorda, Galveston, Fort 
Bend, Liberty, Jackson, and Orange, if they occur there at all. 
Prairie chickens had not been seen in Goliad County for at least 
10 years prior to 1937, at which time four birds were reported on 
the W. J. O'Conner ranch. 

No more than half the grassland range in any county except 
Refugio is occupied by prairie chickens. In the counties of Mata- 
gorda, Lavaca, Wharton, Calhoun, Liberty, Jackson, and Fort Bend 
even less than 10 percent of apparently satisfactory pasture is inhab- 
ited. Roughly, the available range for prairie chickens is only about 
30 percent occupied and, with the exception of about 20,000 acres 
in southeastern Refugio County, all the occupied area has a sparse 
population. 

The total number of prairie chickens in coastal Texas in the 
summer of 1937 was only about 8,700. The estimated 1937 popula- 
tion was probably less than 1 percent of the number believed to 
have occupied the coastal prairie in peak years before it was devel- 
oped by white men. Approximately 4,200 chickens (or almost 50 
percent of the known population of the State) inhabit two ranches 
in Refugio and Aransas Counties. The estimated population of 
4,500 birds for the remainder of Texas is small indeed ! 

The consensus is that, during the past 10 years, the number of 
prairie chickens has decreased in all coastal counties except Refugio 
and Brazoria. In Refugio County there has been a rapid increase 
in recent years, probably largely because of excellent protection on the 
Salt Creek and Martin O'Conner ranches. Since 1935 the birds have 
spread from these onto the O'Brien, Powers, Welder, and Heard 
ranches near Greta, Refugio County, and probably also into Goliad 
County. Because of protection during a 5-year close season in 
Brazoria County (1932-36), R. Z. Cowart, State game warden there 
believes that in 1937 the number of birds had reached and possibly 
slightly exceeded the 1927 population level. 



10 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

The prairie chicken population of the counties of Orange, Liberty, 
Fort Bend, Matagorda, Jackson, Lavaca, Calhoun, and Goliad, where 
populations of less than 100 birds per county obtain, may already be 
reduced to the point where recovery will be extremely difficult or 
even impossible. So long as any birds remain, however, every effort 
should be made to build up their numbers. 

HABITS 

COURTSHIP AND MATING 

Prairie chickens do not pair for breeding, but are promiscuous. 
Males occupy selected courtship stations on booming grounds (see 
frontispiece) , which are visited by the females. Copulation may take 
place elsewhere, however, in case of chance meetings. To attract the 
females, the cocks put on elaborate exhibitions, and their courtship 
antics are unbelievably weird. Of special interest is the manner 
in which the booming call is rendered. 

This call of the male resembles somewhat the sound whur-ru-rrr^ 
with strong accent on the second syllable. Although it generally 
lasts about 6 seconds, the call varies in length and tone. In mid- 
season the calls are characteristically deep and full-throated; later 
they become shorter and higher pitched, possibly because the males 
are then less vigorous. The sound of the booming carries for a 
mile or more on quiet days. It has a ventriloquial effect and often 
seems farther away or closer than it actually is. During the court- 
ship season males boom regularly in early morning (sunrise until 
about 8 a. m.) and in late afternoon (5:30 p. m. until sunset), but 
calls have been heard at all hours of the day and night. Booming 
at night is sporadic, however, even during the peak of the courtship 
season in March, being most common when the moon is bright and 
when there is little wind. 

The appearance of the male, while booming, is striking. As a 
preliminary to uttering the call he stretches his neck forward par- 
allel to the ground. The erected pinnae, or neck tufts, point for- 
ward; the spread tail is held vertically or even inclined slightly 
over the back. The wings are extended downward and held firmly 
against the body and legs, the primaries almost touching the ground. 
The whole body appears strained and rigid. A short run forward is 
followed by vigorous stamping with the feet, which lasts only a few 
moments, but which under favorable conditions is distinctly audible 
for 50 feet or more. Inflation of the air sacs, which are actually 
but one sac with two lateral portions (pi. 3) is synchronized with 
the stamping. The first syllable of the booming is given before 
stamping ends, the male quickly jerking his head downward as he 
begins the call and keeping it there until the air sac is deflated. 



North American Fauna 57, Fish and Wildlife Service 



Plate 3 







Male Attwater's prairie chicken, showing vocal sacs. (Photo from Texas Game, 
Fish, and Oyster Commission.) 



ATTWATER'S PRAIRIE CHICKEN 11 

The call of Attwater's prairie chicken apparently is given in the 
same manner as was that of the extinct heath-hen, its near relative. 
Gross (Bent 1932: 272) describes the booming mechanism of the 
heath-hen as follows : 

The sacs do not produce the notes, as was thought by some of the earlier 
ornithologists, but have much to do with modifying the sounds produced by 
the syrinx (the vocal mechanism at the juncture of the bronchial tubes). The 
sounds are produced by the air forced from the lungs, which vibrate specialized 
membranes of the syrinx under control of a complex set of muscles. The 
sound waves then issue through the trachea and glottis to the pharynx. In 
the production of such notes as the ordinary cackle the mandibles are opened 
and the air accompanied by the sound waves issues out of the mouth. In the 
tooting [booming] performance the mandibles are tightly closed, the throat 
patch is elevated, and the tongue is forced against the roof of the mouth 
(palate) by the mylohyoides muscles, which close off the exit through the 
Internal nares. The tongue is bent in such a way that it causes the glottis at 
the base of the tongue to open directly in front of the esophagus. The air 
now coming from the respiratory system is forced to fill the modified anterior 
end of the esophagus, or gullet, which becomes distended like a balloon. While 
the air sac is filling, the sound waves produced by the syrinx beat against 
these tense drumlike membranes, which serve as resonators for the sounds 
and give them their great carrying power. 

The booming call does not complete the vocabulary of male prairie 
chickens at courtship time. The rendition of additional calls, all 
distinctly henlike, is described as closely as possible on p. 12. On 
windy days cackling sounds, like Nos. 1, 2, and 3 in the list, carry 
farther than booming. The call note picoik (No. 14) dominates 
when hens visit the courtship grounds. Observers may identify 
grounds where females are present by this piooik call. 

Males do not confine their courtship activities to vocalizing, and 
fights are common. Opponents usually approach each other, utter- 
ing peculiar whining notes, with necks outstretched, ear tufts erected, 
tails spread, wings drooped, and air sacs deflated. Then, as if pos- 
sessed of the same thought, they suddenly hop off the ground, wings 
beating rapidly, and clash in midair. These bouts are usually dis- 
continued after three or four flurries, and the victors seem satisfied 
after pursuing their opponents for short distances. Many feathers 
are frequently lost, but fights seldom if ever end fatally. Males 
sometimes engage fancied opponents, as clumps of weeds or tufts 
of tall grass, and at other times they joust and bluff for periods up 
to 30 minutes or more without striking a blow. With necks out- 
stretched, heads held a few inches apart, and wings dangling loosely, 
they resemble domestic roosters fighting. At intervals males flutter 
into the air to heights of 3 to 5 feet, alighting nearly on the spot 
whence they arose. Their surplus energy apparently must be expended 

303807°— 41 2 



12 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

in one way or another, although activity sometimes lags for brief 
periods. 

CALL OF MALE PRAIRIH CHICKENS ON COURTSHIP GEOTJHDS 

1. Ca-ca'-ca-ca-ca-ca-ca-cor-caa-ccui—. All except last two notes given rapidly. 

2. Ca-ca'-caa, ca-ca'-caa Rapid. 

3. Ca-ca-ca-ca'-ca Rapid, accent on second to last syllable. 

4. Ca-ca-ca-corkeeee All except last syllable given rapidly. 

5. Ktmeee, ca-ca-ca-oa-ca-ca First syllable drawn out^ remainder given 

rapidly. 

6. Kwerr-hwerr-pwah First two syllables drawn out. 

7. Ewier-kwier-kicier-kivier All syllables drawn out. 

8. Pwark or pwarrk Medium rapid. Often preceeds cackling 

or booming, carries as far as or farther 
than booming notes under certain 
weather conditions. 

9. Caaa-caaa-caaa-caaaa Slow and drawn out. Sounds almost ex- 

actly like protests of a domestic setting 
hen that is disturbed. 

10. Piviek, pioark Medium rapid. 

11. Piviek, pwiek, pwiek All notes drawn out with emphasis on 

the iek. 

12. Pioiek, ca-ca-ca-ca-ca-caa Pause after first note, cackle given rapidly. 

13. Pivk-pivk-pwk-pwk-pick-pwk Harsh notes executed rapidly, but in a 

subdued tone. 

14. Pwoik, pwoik, pwoik, pwoik Executed rapidly and with much vigor. 

These notes predominate all other calls 
when a female approaches a courtship 
ground. 

15. Kliee, kliee, kliee; corca-ca-ca— Kliee's drawn out ; ca's given rapidly. This 

is a prominent call in early spring. 

16. Kwoo, kivoo; kwah, kivah Rapid. Another prominent early season 

call. 

The performers do considerable feeding when they first arrive on 
the courtship ground, and certain of them feed sporadically throughout 
their stay. At other times individuals, sometimes an entire group, sit 
or stand in their places and look about. Rest periods terminate 
abruptly, however, when a male recognizes a real or fancied challenge, 
or when a hen appears. 

While the male is bold and noisy during the mating season, the female 
is demure and shy. Hens visit the courtship grounds irregularly except 
early in March. Even in well-populated territory a week sometimes 
elapses before the persistent male performers are rewarded by female 
company. When on or near a drumming ground, hens usually appear 
little interested in the spirited antics of the ob\aously excited males. 
Sometimes, however, they walk among the contestants and mate with 
one or several of them. Hens usually remain at the courtship areas 
briefly; usually they stay only a few minutes before leaving to feed 
elsewhere or fly to the vicinity of their nests. 



ATTWATER'S PRAIRIE CHICKEN 13 

In Colorado County signs of the approaching breeding season w^re 
noted early in January (1937) and late in December (1938) when cer- 
tain males, probably the most vigorous, pecked at and otherwise bullied 
their fellows as the flocks left the roost or fed early each morning. A 
few weeks later, early in February (1937), and late in January (1938), 
males assembled early in the morning on short-grass areas that later 
served as courtship grounds, and fought and maneuvered for choice 
positions. For a week or more, calls consisted largely of miscellaneous 
squawks and cackles, and fights, though frequent, were of short dura- 
tion. Males occasionally attempted to drum or boom, but their notes 
lacked midseason depth and vigor. Females, still in winter flocks, 
seemed indifferent to the proceedings. It was not until February 12, in 
1937, and January 26, in 1938, that booming was commonly heard, and 
each year, after 2 to 3 weeks, flocks of females generally broke up and 
the courtship season was well under way. During both 1937 and 1938 
courtship activity was at its peak in March, continuing through April 
and ending on May 20, in 1937, and on May 21, in 1938, when the last 
booming calls were heard. 

Key areas during the courtship season are the booming grounds where 
males assemble each morning from daybreak until about 8 a. m. and 
each afternoon from 5:30 p. m. until dark and give their courtship 
display. 

The preferred booming ground is a short-grass flat, an acre or so in 
extent, surrounded by an area of medium to heavy grassy cover suitable 
for nesting. Of several hundred sites observed during 3 years (1936- 
38) only one was on ground elevated enough to be termed a small knoll. 
The others were even with or slightly below the adjacent land surface. 
Stoddard (Bent 1932: 245), discussing the greater prairie chicken in 
Wisconsin, says that "the 'cooing' ground [courtship ground] at the 
sandy west end of Sauk Prairie has been used each spring for over 30 
years, the birds always using the same knoll whether in rye, stubble, 
or grown to grass." Courtship grounds of Attwater's prairie chicken 
do not show the same degree of permanence. Cultivation seemingly re- 
sults in immediate eviction, whether the crop is rice, corn, cotton, or 
something else. Likewise, the birds do not use fallow fields except where 
cultivated land is the only other environmental type available, or where 
the fallow land has aged to the extent that its surface and vegetation 
are nearly identical with that of nearby grassland. Even those court- 
ship grounds that are in pastures may or may not be occupied each year 
for a series of years. Of 10 such grounds, on which records were ob- 
tained from 1936 through 1938, only 5, or 50 percent, were occupied each 
year. Their populations were fairly stable (see table 3, p. 14). Of 
the others, 2 were occupied in 1936 and 1937 ; 2 were unused except in 
1936 ; and 1 was occupied in 1936, in part of 1937, and throughout the 
entire season in 1938. There was little variation in the prairie chicken 



14 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

population of the pastures in which these courtship grounds were situ- 
ated, but in every instance the vegetation on or near the study areas 
varied in density through grazing or burning. Cover changes on and 
near courtship areas influenced their attractiveness to the birds, possibly 
to the point of determining whether they would be occupied and by 
how many individuals. 



Table 3.- 



-Occurrences in 3 years of male prairie cMckens on 5 courtship grounds 
in Colo7~ado County 





Observations 


Birds observed 


Name of pasture 


Extremes 


Averages 




1936 


1937 


1938 


1936 


1937 


1938 


1936 


1937 


1938 


Thomas 


2 
2 
2 
2 
2 


11 
8 
14 
13 
20 


6 
6 
6 
11 
12 


7- 9 
9-11 

5- 6 

6- 8 

7- 7 


6- 9 
3-10 
3- 9 
5-11 
0- 8 


4-11 
5- 8 
3- 8 
5-13 
6-14 


8.0 
10.0 
5.5 
7.0 
7.0 


7.0 
6.0 
8.0 
9.0 
6.0 


8.0 


Do 


7.0 


Do 


7.0 




10.0 


Everett 


10.0 






Total or average 


10 


66 


42 








7.5 


7.2 


8.4 











NESTING 

WMle the males are still engaged in their courtship performances, 
the females quietly select and improve the nest sites and attend to 
laying, incubating, and hatching the eggs and rearing the young. 
Nests (pi. 4) are made on the ground. Of 19 examined in 1937 
and 1938, 17 were in long-grass pastures, 1 in a hay meadow, and 
1 in a fallow field. All were in dead grass of the previous year's 
growth. Fifteen (about 76 percent) were on or near well-drained 
mounds or ridges, and 4 were in poorly drained situations. In a 
choice of nest sites, cover appeared of more importance than topog- 
raphy and the structure of the soil. Twelve (63 percent) of the 
study nests were situated within 10 yards of well-marked trails, 
possibly because prairie chickens dislike walking through heavy 
matted vegetation when approaching or leaving their nests. Cattle 
make many trails, thereby improving nesting areas. 

Study nests were found always within a radius of half a mile 
to a mile from occupied booming grounds. Sometimes the sites were 
rather distant from acceptable feeding territory, although flights of 
up to a mile seemed to inconvenience the birds very little. 

Nests were merely shallow depressions, about 7 inches in diameter, 
lined with bits of dead grass, twigs, and a few feathers, presumably 
from the females. All were more or less roofed over because of the 
lapping or bending over of surrounding vegetation. Entrances faced 
in various directions with no preference shown. There was consid- 
erable variation in degree of concealment (pi. 5), at least according 
to human standards; 5 nests being excellently, 10 well, and 4 poorly, 
concealed. Kapid new plant growth in April and May aided ma- 



North American Fauna 57, Fish and Wildlife Service 



Plate 4 




OJ 



« 5 






P O 



3 5 
-2 ^ 






> CL, 



>< 



North American Fauna 57, Fish and Wildlife Servii 



PLATE 5 




'.■^- ' 




^ QJ O 






>i <»" r^- 



^O 



ATTWATER'S PRAIRIE CHICKEN 15 

terially in hiding nests ; consequently, some nests that were relatively 
exposed when found were well hidden later. Wild indigo {Baptisia 
sp.), vetch {Vicia ludoviciana) , phlox ( Phlox drummondii)^ peren- 
nial ragweed {Amhrosia psilostachya) , dogfennel {EupatoHum sp.), 
and panic grass {Panicuin sp.) were green plants that aided con- 
cealment materially by mid-May. In Colorado County, favorite 
nesting materials were dry bluestem grass {AndropogoTi scoparius), 
and paspalum {Paspalum dilatatum). 

The earliest date for a nest containing eggs was reported by Wad- 
dell near Egypt, Wharton County, February 25, 1925; the latest 
record is that of a nest in Colorado County in which the clutch 
was completed May 29, 1938. In both 1937 and 1938, however, the 
peak of the laying season in Colorado County was late March and 
early April. Hens always laid in the morning, usually from 7:30 
to 9, flying to the vicinity of their nests when ready. After cautiously 
looking about or feeding a bit longer, hens walked to the nests and 
remained there for from about 20 minutes to an hour. The laying 
completed, they regularly walked about 20 feet from the nest, scanned 
the landscape, and flew away. Since incomplete clutches were un- 
guarded except during about an hour each day, they were especially 
vulnerable to natural enemies. 

Hens under observation normally laid an Qgg a day until the 
clutch of 8 to 15 was complete, but sometimes they failed to lay for 
periods of 1 to 3 days. Clutches usually contained 12 eggs, and lay- 
ing was generally completed in about 2 weeks. The period of egg 
laying was sometimes extended, however, when nests were destroyed. 
Three hens, each the only resident on a small unburned plot, re- 
nested during 1937, one of them three times. 

New nests, however, were placed 5 to 20 yards from old ones, and 
were less effectively concealed. Destructive agents had even greater 
opportunities to take the later nests, as they did in four out of five 
cases. Since booming ended by mid-May, the period for mating 
was short. Late broods were invariably smaller than early ones, 
probably because late clutches were small, their hatchability low, or 
their mortality heavy. A successful season depends largely on the 
fate of early nests, so that a primary objective of management should 
be to safeguard these attempts. 

Twenty-nine eggs of Attwater's prairie chicken measured by Bent 
(1932: 264) averaged 42.3 by 31.5 millimeters in size, showing ex- 
tremes of 44.9 by 32, 42.4 by 33.5, 38.8 by 28.9, and 39.8 by 28.6 
millimeters. Newly laid eggs were dull cream or bluish buff in 
color, some of them minutely specked with red. During incubation 
the color of the eggs became dull and the shells shiny. Incubation 
began at from 1 day before until 4 days after the last egg was laid. 



16 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

Except for two feeding and resting periods daily, extending from 
about 7 to 8 a. m. and from 5 :30 to 6 :30 p. m., hens incubated con- 
stantly. When incubation was advanced, morning feeding was fre- 
quently dispensed with. Two clutches pipped approximately 23 and 
24 days after setting began, in each instance requiring about 48 hours 
longer to hatch. Of 71 eggs in 7 nests, only 3 (about 4 percent) 
were infertile, 66 hatching successfully. Seemingly, fertility and 
hatchability are high under favorable conditions. 

The hatching period was evidently a time of danger. Chicks 
peeped incessantly and scrambled in and out of the nest. Nests 
emitted strong odors, apparent even to man. Females at hatching 
time appeared nervous and shifted their positions frequently. Unless 
disturbed, however, they did not leave until the last egg had hatched, 
after which they deserted the nests. In 1937 a nest in which all 
young were hatched by 11 : 50 a. m. on May 15 was vacated by 3 p. m. 
that day, and a brood that was hatching at 8 : 30 a. m, on June 2 was 
gone 24 hours later. One hen left before 2 pipped eggs were hatched 
and before the natal down on some of the young was dry, probably 
because fire ants {SoUnopsis) had entered the nest. 

GROWTH AND DEVELOPMENT OF YOUNG 

When leading chicks from the nest, old birds traveled through 
the lightest cover or followed trails, probably because heavy matted 
vegetation impeded progress and increased the chance of chicks get- 
ting lost. Cow trails were favorite travel ways. Chicks ranged in 
front, behind, and on both sides of the hen over an area 1 to 5 yards 
in radius. Interruptions for sporadic feeding and for frequent 
brooding, which was probably more necessary for assembling than 
for warming the young, made progress slow. Hens with chicks less 
than 10 days old (pi. 6) seemed mainly concerned with watchfulness 
and brooding. Occasionally they caught available insects or nipped 
off a few green leaves or buds, but they did little continuous feeding. 
When danger threatened, they gave a warning call, best described 
as a low kwerr^ kwerr, kiuerr, and slowly skulked through the grass 
with head lowered and wings dangling loosely, almost touching the 
sod. Young birds "froze" with their bodies closely pressed to the 
ground. Decoy efforts of adult females were never so energetic as 
those of bobwhites under similar circumstances. When hens were 
flushed, the chicks in hiding (pi. 6) became impatient after 3 to 5 
minutes, and peeped and ran about in spite of the fact that the object 
of suspicion remained. After the immature birds of 2 to 3 weeks 
of age could fly fairly well, females accompanying them did not 
decoy, but always flushed freely, the young doing likewise. 

Chicks that were less than a week old were brooded quite often, 
probably in all for about 50 percent of the daylight period. Ten birds 



North American Fauna 57. Fish and Wildlife Service 



Plate 6 




Ahopc, Chicks about 10 days old; Colorado County, 1 ex., n|)i)i().\iiiiai«-ly (1 miles 
north of Eagle Lake, May 3, 1938. Below, Chicks hiding; Colorado County, 
Tex., approximately i^Yz miles north of Eagle Lake, May 3, 1938. (Photos 
from Texas Game, Fish, and Oyster Commission; E. P. Haddon.) 



ATTWATER'S PRAIRIE CHICKEN 17 

about 2 days old were brooded 42 minutes out of the li^ hours during 
which they were watched on May 4, 1937. Their position during 
brooding was interesting. Hens squatted low with legs at an angle 
of about 30 degrees with the ground. Wings were drooped and 
feathers of the underparts were ruffled. Some chicks scrambled up 
and under the wings. When the brooding hens were frightened and 
suddenly stood erect, usually only two or three chicks were visible; 
the others, however, tumbled from beneath her wings a few moments 
later. As the chicks grew older, the time spent brooding diminished ; 
those 2 weeks old apparently were brooded little except early in the 
morning, during inclement weather, and at night. 

Newly hatched chicks are about the gize of day-old bantams, and 
their coloration is nearly identical with that of young bronze turkeys. 
The basic, buffy yellow is streaked with gray on head and upper- 
parts. Growth and development are rapid. Wing feathers appear 
almost at once; week-old chicks have primaries approximately five- 
eighths of an inch long. Chicks fly when 2 weeks old. Except for 
differences in the length of the tail and legs, they are about the size 
of English sparrowg. When 3 weeks of age, youngsters are almost 
as large as starlings and can make sustained flights of 40 yards or 
more. At 4 or 5 weeks, young birds approximate the size of mature 
bobwhites, and often fly a hundred yards before alighting. When 
6 or 7 weeks old, the young are about half grown and at 8 or 9 weeks 
they are three-fourths the size of adultg. Youngsters 10 to 12 weeks 
old can scarcely be differentiated from the old birds in the field. 
Weight evidently does not increase as rapidly as size, however, for 
two birds approximately 3 months old were more than a pound lighter 
than mature individuals. 

As young prairie chickens grow in size, all cannot, of course, main- 
tain a brooding position under the sheltering body of the mother. 
Usually by the time they are about 3 weeks old some are forced out- 
side; there they sleep with bodies pressed closely to that of the hen. 
When 4 to 5 weeks of age, two or three chicks sometimes crowd under 
their mother, but the remainder roost from a few inches to about 2 feet 
away. At 6 to 7 weeks, young birds adopt the roosting formation of 
adults. Flocks of Attwater's prairie chickens sleep about a foot or so 
apart, the individuals facing in different directions. Boosting spots 
vary in size from 1 to 3 square yards or more, depending on the number 
of birds in the group. The number of scats left at a roosting site 
is not an absolutely accurate index to the number of birds in a flock, 
because slight shifting of individuals during the night brings about the 
deposition of more than one pile by a bird. 

Chicks about 2 weeks old take vigorous dust baths, a habit that is 
indulged in regularly throughout life when dry, powdery material is 



18 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

available. Prairie chickens generally dust during the midday rest 
period that extends from about 10 a. m. to 4 p. m. Old pocket gopher 
mounds and cattle wallows are favorite places. Some birds use the 
same dust bath more than once. 



BROOD SIZE 

The size of the brood generally decreases with the age of the young. 
Of 48 broods on which accurate counts were kept (table 4, below) 6 
from 1 to 3 days old contained 64 young, averaging 10.6 birds each. 
Three broods estimated to be 5 to 10 days old contained only 14 chicks 
averaging 4.6 each. Four broods 15 to 27 days old had 22 young, or 
an average of 5.5. Fifteen families over 4 and under 6 weeks of age 
aggregated 80 young and averaged 5.3. Twenty groups over 6 weeks 
totaled 80 young and averaged 4 each. The average size (5.3 young) 
of 15 families, estimated to be over 4 but under 6 weeks of age, was 
exactly half the average size (10.6) of 6 new broods. The average 
size (5.3) of 15 families over 4 but under 6 weeks old was but slightly 
larger than the average size (4.0) of 20 families older than 6 weeks. 
Therefore, it appears that juvenile mortality is heaviest during the 
first 4 weeks and comparatively light thereafter. 



Table 4. — Size of iroods and number of chicks counted during May, 

July 


June, and 


County 


Date 


Family 

groups 

observed 


Chicks 

per 
group 


Chicks per 
average 
group 




May 4 
May 15 
May 18 
May 23 
May 28 
May 29 
May 31 


1 

1 
1 
3 
3 

1 
2 


10 
12 

12 

2,4,2 

7, 9, 11 

8 

4,8 


10.00 


Do 


12.00 


Do 


12.00 


Do - 


2.66 


Do 


9.00 


Do --- 


8.00 


Do - 


6.00 








12 


89 


7.41 




June 2 
June 3 
June 8 
June 10 
June 24 






4 
1 
2 
2 

3 


6, 9, 4, 2 

10 

3,3 

4,8 

5,4,3 


6.33 


Do 


10.00 


Do 


3.00 


Do 


6.00 


Jefferson 


4.00 


Total or average for June 


12 


61 


5.08 




July 1 
July 8 
July 14 
July 17 
July 19 
July 26 


3 
2 
1 
4 
6 
2 


5,5,6 

3,3 

7 

10, 8, 1, 3 

10, 2, 2, 4, 5, 2 

10,5 


5.33 


Colorado 


3.00 
7.00 




6.00 


Do 


4.16 


Colorado 


8.00 


Total or average for July 


18 


92 


5.11 




Aug. 12 
Sept. 2 
Sept. 3 
Sept. 4 


1 
3 
1 
1 


3 

5,3,3 

3 

4 


3.00 




3.66 


Do 


3.00 


Do 


4.00 


Total or average for August, September 


5 


18 


3.60 






48 


263 


5.48 









ATTWATER'S PRAIRIE CHICKEN 19 

JUVENILE MORTALITY 

Although much remains to be learned about juvenile mortality, 
its causes were fairly well established in some instances. Chicks are 
sometimes trapped and drowned in rice fields at the time of flooding 
(usually about May 10). In 1925, near Egypt, Wharton County, 
Waddell and others picked up hatfuls of chicks and carried them 
beyond the levees. In 1937 a farmer near Eagle Lake similarly res- 
cued a brood. The number of chicks annually saved from this 
hazard, however, is probably insignificant in contrast to those lost. 
Prairie fires kill young and, as stated on page 42, burning is still 
common in certain areas at nesting and brooding time. Unfavorable 
weather, especially rains (pp. 32 to 35) and natural enemies (p. 39), 
account for the death of some young birds, but no small percentage 
of these may be chicks that are lost. 

Chicks stray from the brood more often than one might suspect. 
During April, May, and June, 1937, no fewer than 13 strays were 
seen, all under 4 weeks old. Usually they occurred as singles, but 
sometimes in pairs and trios. How the youngsters became lost, of 
course, was usually unknown, but several reasons were apparent. 
The characteristic loose feeding formation of broods possibly con- 
tributed to straying; also, broods usually scattered widely and flew 
far when disturbed; and, possibly most significant of all, adults did 
not appear to have a highly developed rallying call that doubtless 
would be of assistance in reassembling youngsters. 

Lost chicks evidently join other groups occasionally, as hens ac- 
companied by young of varied sizes were several times noted in 1937. 
Once two chicks, about 2 and 3 weeks old, respectively, were seen 
with two molting males. Higher population levels might increase 
the frequency of adoptions. 

FAMILY DISINTEGRATION 

Many young Attwater's prairie chickens 6 to 8 weeks old leave the 
family groups and take up life on their own, but, as is true with 
domestic chickens, all young do not leave the hen at the same time; 
disintegration of the family group is gradual. Some young remain 
with the hen well into the fall. Unattached young, 6 weeks of age 
or older, as distinguished from lost chicks less than a month old, 
became noticeable late in June and they were frequently seen after 
July. Family disintegration after 6 weeks or thereabouts is normal. 
Young prairie chickens at that age seem as capable of foraging and 
resisting adverse weather as are the adults. 



20 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

ANNUAL INCREASE 

The actual survival of young prairie chickens (table 5, below) prob- 
ably is always well below the potential yield (12 or so young from 
each hen) even when favorable weather conditions obtain during 
the critical breeding season. 



Table 5 


. — Young and adult Mrds observed 


in census after June 30, 1937 




Date 


Area 


Adults 


Young 




County 


Males 


Females 


Sex un- 
known 


Total 


Families 


Strays 


Total 


Brazoria 

Victoria 


July 1 
July 14 
July 17 
July 19 
July 26 
July 27 
Aug. 12 
Sept. 1 


Acres 
585 
921 

1,080 
530 

1,450 
851 

1,282 

2,000 


Number 
2 
1 
1 
3 

2 
1 
1 


Number 
4 
1 
4 
8 
2 

1 
5 


Number 
2 
6 

23 
S3 
4 
2 
2 
8 


Number 
8 
8 
28 
64 
6 
4 
4 
14 


Number 

5,5,6 

7 

10, 8, 1, 3 

10, 2, 2, 4, 5, 1 

11,5 

3 

3 

5,3,3 


Number 

1, 1, 1, 1, 1 

1,2 

2, 1, 1, 1, 1 

1, 1, 2, 1, 1, 1 

2,3 

1 

1 

1,2,1,3 


Number 
21 
10 


Refugio 


28 


Do 


32 


Colorado. 

Brazoria 

Harris . . 


21 

4 
4 


Colorado 


18 


Total 


8,699 


11 


25 


100 


136 


103 


35 


138 









In a rope count on or after July 1, 1937, 138 young as compared 
with 136 adults (about 1:1) were enumerated on an area of more 
than 8,699 acres. At this time most of the counted birds were 4 
weeks old or more and were beyond the age when mortality is thought 
to be most severe. The increase on the counted areas, then, was only 
about 100 percent in spite of the fact that food, cover, and weather 
conditions were favorable. A 100 percent increase of prairie 
chickens in any one year is very good, and the arguments for long 
open seasons and large bag limits, based on the potential annual 
increase (12 chicks for each hen, or about 600 percent a year), evi- 
dently are fallacious. 



FLOCKING 



Late in summer and early in fall, the prairie chickens displayed no 
marked tendency to combine into stable groups. In August and 
September of 1936 and 1937 well over half the birds observed in 
Colorado County were recorded as singles, pairs, and trios, although 
small groups of 4 to 6 were not uncommon. Occasional larger flocks 
were recorded, but these appeared to be temporary. In Colorado 
County, at about noon on September 1, 1937, a flock of 15 to 25 birds 
was noticed in a cotton field. On the following 3 days at the same 
hour 11, 15, and 9 birds, respectively, were present in that field; 
but they had come in between 9 : 30 and 11 : 30 as singles, pairs, and 
in small groups not exceeding 5 birds each. Between 4 p. m. and 
dark they left the field as they had come. Again in Colorado 
County, at 6 p. m. on September 3, 1937, another group of 16 birds 
found in a pasture came together as follows : At 5 : 40 p. m. a group 



ATTWATER'S prairie CHlCKElSr 21 

of 8 flushed approximately 1 mile from the spot where the large 
flock was later noted, and as they flew over the prairie, a pair, a 
single, a trio, and another pair joined the original group. AH set- 
tled and fed together for a time, but the be\^ disintegTated by dusk. 
Like instances suggest that early fall flocks of a dozen or so birds 
are unstable groups brought together largely by chance. 

In fall, after the weather turned cool, groups of prairie chickens 
became the rule rather than the exception. Early November bevies 
generally contained 4 to 12 birds each, but large flocks became in- 
creasingly common from about December 1 to the onset of the breed- 
ing season. Late in winter (January) Guy Ferguson, State game 
warden, Sinton, Tex., observed flocks in Kefugio and Aransas Coun- 
ties that contained more than a hundred birds. Wardens Waddell 
in Colorado, Austin, and Wharton Counties, and McClosky in Vic- 
toria County, reported winter aggregations of about the same size. 
In 1936, J. O. Linney, foreman, Salt Creek (Hallahan) ranch, Re- 
fugio and Aransas Counties, noticed late winter concentrations esti- 
mated to contain 250 to 300 individuals. The writer has not observed 
such large winter flocks, possibly because he has not made observa- 
tions in areas where the birds were sufficiently numerous. January 
assemblages of 25 to 35 birds were not uncommon, however, in Colo- 
rado County. Despite the fact that large flocks became more fre- 
quent from November until the breeding season, small groups of 8 
or fewer birds or singles were always to be found. All packs ob- 
served in Colorado County late in November, December and January 
contained birds of only one sex. Late in January, residents of the 
coastal country eagerly listen for the first booming calls, which, 
besides promoting rapid disintegration of winter flocks, signal the 
departure of winter and the coming of spring. 

seasonal movements 
Spring 

Comprehensive data on prairie chicken movements are lacking, but 
the records obtained in 1937 are of interest. Two broods that were 
observed two or more times daily from the time the}?^ were hatched 
until they were 7 and 12 days old, respectively, were, at last observa- 
tion, less than half a mile from the nest sites. Another brood, esti- 
mated to be 8 days old when first discovered on June 2, was within 150 
yards of the same spot at various hours during the next 6 days. A 
fourth brood, about 3 days old on April 29, remained within 400 yards 
of a certain windmill from April 29 through May 31. A 640-acre 
pasture that contained four broods, all under 2 weeks of age when 
rope counted on June 2, likewise harbored four broods 10 days later. 



22 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVlCiJ 

If this is indicative, the prairie chickens under observation spent 
their first several weeks of life in close proximity to the places where 
hatched. The daily cruising radius of a brood apparently was small, 
seemingly less than 300 yards in the case of birds under 4 weeks old 
in a favorable environment. Some 30 broods observed between May 
1 and June 1 were found in light cover on or near hardpan flats and 
recent burns, indicating a distinct preference for those types of habitat. 

SUMMEE 

An extensive movement involving both young and adult prairie 
chickens in Colorado County began about June 1, 1937, when many 
of the young were 3 to 5 weeks old, and lasted until about June 
30. The sudden scarcity of the birds in places where they had been 
common only a few days before was striking. A 1,000-acre pasture 
that contained 37 individuals (16 old and 21 young) on June 2, held 
only 16 in all on June 10. As the prairie chickens decreased in some 
pastures, they increased in others. A 460-acre pasture that was un- 
occupied on May 1 contained 14 birds on June 8 and 23 on July 26. 

This movement from the spring range was by stages. One brood 
that was watched closely made trips of approximately 1 mile, three- 
fourths mile, and 1^ miles in 6 days from June 2 through June 8. 
After the first major movement, this family remained for 3 days in an 
area less than 500 yards in diameter ; their droppings in piles formed a 
triangle with sides of 5, 15, and 17 yards, respectively. The move- 
ment of a combined brood of 3 hens and 16 to 25 young are recorded 
in figure 2, p. 23. 

Leopold (1933: 291) reports thai^- 

All observers unanimously and independently report a strong tendency for the 
grown young of most species of grouse to seek the vicinity of drinking water 
in late summer and fall, but whether they do this out of choice or necessity 
is not known. 

The early summer movement of young and adult Attwater's 
prairie chickens also was to the vicinity of surface water, but it 
was to water near which there also was shade. Pastures having an 
abundance of surface water but little or no shade-producing cover 
had few if any birds after mid-June. Likewise, places in which 
dense stands of weeds, shrubs, or tall grass were abundant, but sur- 
face water scarce, were sparsely populated. More than 95 percent of 
the more than 600 Attwater's prairie chickens observed from June 
24 through September 4, 1937, were in heavy cover within a mile, 
generally within less than half a mile of surface water. 

The beginning of the summer movement is synchronous with the 
drjdng up of the wild indigo {Baptisia, pi. 7), a plant that fur- 
nishes the principal shade on burns and heavily grazed areas from 
April through May. Prairie chickens require abundant shade in sum- 



North American Fauna 57. Fish and Wildlife Service 



PLATE 7 





B50688: B49718A 



Above, Wild indigo {Baptisia) in a closely grazed pasture; Austin County, Tex., 
approximately 8 miles southeast of Sealy, April 10, 1938. Below, Shocked 
grain and wa.ste in rice fields sometimes attract prairie chickens; Colorado 
County, Tex., 3 miles northeast of Eagle Lake, September 5, 1936. (Photos 
by V. W. Lehmann.) 



ATTWATER'S PRAIRIE CHICKEN 



23 



mer, for birds that were herded from such cover at midday panted 
vigorously, drooped their wings, and showed other signs of discomfort. 
They evidently rarely drink from surface water. In 1937, birds 
near water were closely observed, but only one was seen to drink 
during the entire summer. That was in Colorado County on June 
1, 1937, when a chick about 3 weeks old drank a few times from a 
puddle formed by water from a leaking windmill. The soft mud 
bordering ponds in inhabited prairie chicken range in Brazoria, 
Colorado, and Austin Counties was examined thoroughly at various 
times, but tracks of this species were never found. Grasshoppers 




FiGUBE 2. — Movements of a combined brood, May 1 to July 26, 1937, Colorado 
County. Birds seen in areas as follows : 1, May 1 to 28 ; 2, June 10 to July 
10; 3, July 15 to 26. 

and other favorite foods were frequently more abundant in surmner 
in heavy cover near water, but the food factor was not thought to 
be of great importance at the time. The summer movements of 
prairie chickens to heavy cover near water are not satisfactorily ex- 
plainable on the basis of cover, water, and food, but these habitat 
conditions must be provided where stable populations are desired. 
After they found a satisfactory summer range, the prairie chickens 
moved little until fall, unless their summer territory was depleted 
or that nearby was more suitable. The population of a 460-acre 
pasture in Colorado County remained at nearly the same level (25 



24 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

to 36 birds) from July 26 through September 3, 1937. The birds 
that rested in this area at noon each day, however, foraged and 
roosted largely in adjoining pastures, but their range was never more 
than 114 miles and usually under half a mile. 

Rains in 1937 sufficiently heavy to collect in low spots caused tem- 
porary spreading of prairie chickens from previously occupied areas. 
As the temporary water disappeared, however, the birds again con- 
centrated. 

Fall and Winter 

Populations that had been rather stable in certain pastures in Colo- 
rado County during the summer months of 1937 began shifting early 
in fall. About 25 birds that were summer residents of the M. Shin- 
dler cotton field from July through August were absent after Sep- 
tember 4. Two thousand acres of regularly censused pasture where 
prairie chickens were common in summer contained only 9 birds when 
rope counted on October 22. While the birds decreased generally 
in the large pastures, they increased around small farms near Sealy, 
Austin County ; Lissie, Wharton County ; and Bernardo and Chester- 
ville, Colorado County — territory 5 to 10 miles removed from the 
pastures in which birds had been most common during the preceding 
spring and summer. 

Distances traveled daily were evidently great in some instance^. A 
bird killed by a farmer at 8 a. m. on September 1, 1936, was L .lown 
to have traveled at least 3 miles since dawn, because its cror was 
filled with rice and the nearest rice field was that distant. Two in- 
dividuals, observed for 2 hours on the afternoon of October 22, 1937, 
traveled approximately ly^ miles southeast of the point where first 
seen. When finally flushed, they flew an additional 2 miles or so in 
the same direction. A flock of four birds observed from 4 p. m. to 
6:15 p. m. on January 4, 1938, traveled more than 1% miles. The 
movement was in a circular direction, however, for at nightfall, the 
birds were less than half a mile from the point where they were first 
observed. Cool weather, fall rains, and a seasonal abundance of 
food and cover, especially in the vicinity of farming co nmunities, 
probably were important in promoting the general fall scattering 
and the long daily trips the prairie chickens made in territory that 
was sparsely populated at other seasons. The birds reconcentrated 
in large pastures, however, as fall passed into winter. 

The population of the Everett pasture (640 acres), Colorado 
County, increased from November 3, 1937, through January 28, 1938 ; 
five censuses during that period showing 46, 58, 56 to 58, 73, and 84 
birds, respectively. Excellent food and cover conditions prevailed, 
for the area was lightly grazed. This increase in the number of 
birds apparently resulted from influxes from adjoining areas. After 



ATTWATER'S PRAIRIE CHICKEN 25 

November 15, few fluctuations in numbers between different pastures 
were reported by fence riders and others. Pastures that contained 
the greatest numbers in November and December 1937 also harbored 
the largest breeding populations the following spring. 

The data at hand show that late in fall, probably by about Novem- 
ber 15, the prairie chickens move to pastures where food and cover 
conditions are adequate. Having found such an area, they remain 
until spring. Probably the best way to attract a good breeding 
population, therefore, is to provide suitable food and cover conditions 
during the preceding winter. 

FOOD 

Data on the food of Attwater's prairie chicken were derived mainly 
from analyses of 21 stomachs (crops, or gizzards, or both) and more 
than 200 droppings (scats). Additional information was obtained 
by watching feeding birds at close range through field glasses. Of 
the 21 stomachs, 18 were of adult prairie chickens, 2 of chicks ap- 
proximately 10 days old, and 1 of a juvenile about 7 weeks old. 
Specimens were obtained as follows: 6 in winter (January and 
February), 5 in spring (April and May), 5 in summer (June through 
August), and 5 in fall (September through November). J. H. Gaut 
collected 3 stomachs near East Bernard, Wliarton County, in May 
1905. Over the period beginning September 1936 and ending Au- 
gust 1938, 2 stomachs were obtained in Austin County, 4 in Refugio 
CounVy, and 12 in Colorado County. As the crops and gizzards 
of alH birds found killed by automobiles, predators, poachers, and 
from other causes were saved, it was necessary to collect only 11 
specimens to balance the series according to seasons. 

Except during the breeding season, adult prairie chickens regu- 
larly feed twice daily, early in the morning (dawn to about 8 a. m.), 
and late in the afternoon (4 p. m. to dark). Occasional bits of food 
are picked up throughout the day, but the gullets of specimens col- 
lected about noon are usually empty or nearly so. The food capacity 
of prairie chickens is large. Gullets frequently contain about 20 
cubic centimeters, and the gizzard about 30 cubic centimeters, of 
material. Since the birds ordinarily feed slowly and deliberately, 
apparently selecting their food with great care, it is not surprising 
that their diet in favorable areas is varied. Stomachs have been 
examined that contained 29 kinds of food and more than 1,300 items ; 
stomachs rarely contain less than 13 kinds of food of 500 items. 
Mature birds evidently feed mostly on vegetation at all seasons, 
for the stomachs of 18 adults (table 6, p. 26) contained 88.28 percent 
of plant material and 11.72 percent of insects. Animal matter prob- 
ably ranks higher than plants in the diet of young birds, however, 



26 NORTH AMERICAN FAUNA 57, PISH AND WILDLIFE SERVICE 

for the stomachs of 2 chicks and a juvenile (table 7, below) contained 
88.5 percent of insects. The ratio of plant to animal food varies 
according to season (table 8, below), insects, for instance, apparently 
being eaten in greatest quantity in summer. 

Table 6. — Composition of the stomach ^ contents of 18 adult prairie chickens 



Item 


Stomachs 

in which 

found 


Quantity 
present 


Item 


Stomachs 

in which 

found 


Quantity 
present 




Number 

18 

12 

16 

5 

6 


Percent 

88.^8 

27. n 

55.67 

1.30 

4.20 


Animal matter 


Number 
18 

17 
8 
1 
1 

11 


Percent 

11 7i 


Leaves and stems 

Seeds and pods 


Insects: 

Adults 


10 83 


Buds and flowers 

Miscellaneous '. 


Eggs and larvae.. 

Round worms 

Prairie chicken feathers... 
Qrit . 


0.89 







1 Crops or gizzards, or both. 

' M^oody pod septa, root stocks, and the like. 

8 Trace. 

Table 7. — Composition of the stomach contents of three younff prairie chickens 



Item 


Stomachs 

in which 

found 


Quantity 
present 


Item 


Stomachs 

in which 

found 


Quantity 
present 


Vegetable matter 


Number 
2 
2 
1 


Percent 
11.6 
1.5 
10.0 


Animal matter 


Number 
3 

3 
2 


Percent 
88. S 


Seeds or pods ... 


Insects: 

Adults 


86.0 




Eggs or larvae 


2.5 



Table 8. — Percentage of plant and animal food according to season 



Item 


Spring 


Summer 


Fall 


Winter 


Whole year 


Plants 


94.25 
5.75 


71.0 
29.0 


85.8 
14.2 


95.0 
5.0 


86.51 




13.49 








Total .- 


100. 00 


100.0 


100.0 


100.0 


100. 00 







The data at hand indicate that Attwater's prairie chickens are 
preponderantly granivorous, for seeds and seed pods made up slightly 
more than 50 percent of all the material in the stomachs of 18 adults. 
Much succulent vegetation is eaten, however, including leaves, buds, 
flowers, and root stocks. The birds also consume insect eggs, larvae, 
and adults, as shown in tables 6 and 7. 

Parts of some 50 kinds of plants and more than 65 species of 
insects were identified in the food from stomachs or scats, or by 
observations in the field. The names of these plants and insects 
together with the seasons when they are known to be eaten, are 
listed in tables 9 and 10, pp. 27 and 28. 



ATTWATER'S PRAIRIE CHICKEN 
Taklb 9. — Plant foods (56) of AtHcater's prairie chicken 



27 



Plant 



Marsileaceae: Pepperwort (Marsilea) 

Poaceae: 

Paspalum (Paspalum ciliatifolium type) . - 

Bull grass {Paspalum boscianum ?) 

Paspalum (Paspalum plicatulum).. 

Panic grass (Panicum scribnerianum) 

Panic grass {Panicum spp.) -. 

Crabgrass {Digitaria) 

Sandbur {Cenchrus) 

Hegari {Sorghum vulgare) 

Rice {Oryza saliva) 

Corn {Zea mays).-. 

Cyperaceae: 

Beakrush (Rynchospora) 

Sedge {Carei)- 

Commelinaceae: Dayflower {Commelina cris- 

pa). 
Alliaceae: Wild onion {Nothoscordum bivalve)... 

Liliaceae: (Undetermined) 

Lcucojaceae: Stargrass {Hypoxis) 

Convallariaceae: Solomons seal {Polygonatum 

commulalum) . 
Ixiaceae: Blue-eyed-grass {Sisyrinchium va- 

rians). 
Polygonaceae: Dock (Rumex near crispus type), 
Ranuneulaceae: Buttercup {Ranunculus near 
hispidus) . 

Rosaceae: Dewberry {Rubv^) 

Malaceae: Chokeberry {Pyrus) 

Mimosaceae: 

Sensitive briar {Neptunia Lutea) 

Mimosa {Mimosa) -. 

Acacia {Acacia)... 

Cassiaceae: Partridge-pea {Chamaecri»ta fas- 

ciculaia) . 
Fabaceae: 

Wild pea (undet.) .-. 

Wild pea {Lathy ruspusillus).. 

Peanuts {Arachis hypogaea) 

Oxalidaceae: Woodsorrel {Oxalis) 

Euphorbiaceae: 

Doveweed(Cro<on capitatui) 

Doveweed (C glandulosus) -. 

Doveweed (C. monanthogynut) 

Spurge {Euphorbia) 

Spurge ( Crotonopsis linearis) 

Spurge (Chamaesyce) 

Vitaceae: Grape (Vilis) 

Malvaceae: Mallow {Malva) 

Epilobiaceae: Gaura {Qaura) 

Ammiaceae {Cynosciadium) 

Convolvulaceae: 

Bindweed {Convolvulus) 

Evolvulus 

Polemoniaceae: Phlox {Phlox drummondi) 

Boraginaceae: Gromwell {Lithospermum) 

Verbenaceae: 

Fog fruit (Phyla nodiflora) 

Verbena (Verbena) 

Acanthaceae: Ruellia (Ruellia ciliosa var. 

humilis). 
Rubiaeeae: 

Buttonweed (Diodia teres) 

Buttonweed (Diodia virginiana) 

Bedstraw (Galium) 

Ambrosiaeeae: 

Marsh-elder (Iva ciliata) 

Perennial ragweed (Ambrosia psilostachya) . 
Carduaceae: 

Thistle (Carduus) 

Tickweed ( Coreopsis) 

Cichoriaceae : {Serinea oppositifolia) 



Parts eaten 



Leaves. 



Leaves, seeds. 

Seeds. 

do.. 

do.. 

do 

do 



.do. 
.do- 
-do. 
.do- 



do 

Seeds, leaves.. 
Leaves, seeds. 



Leaves, flowers. 

Seeds 

Leaves, seeds... 
Seeds.- 



Seeds, pods. 



Seeds 

Leaves, seeds, pods. 



Seeds, fruits 

Flowers, fruits. 



Leaves, flowers, seeds. 

Leaves, seeds.. 

Seeds 

Seeds, flowers 



Flowers 

Leaves 

Fruits 

Leaves, seeds. 



Seeds 

do. 

Seeds, leaves. 

Seeds 

do 

do 

Seeds, fruits.. 
Seeds, pods.. 

Pods.. 

Leaves 



Seeds 

Seeds, pods. 

Seeds, pods, flowers. 
Seeds 



Leaves, flowers, fruit 

Leaves 

Leaves, stems, seeds, 
buds, pods, flowers. 



Seeds 

do... 

Leaves, seeds. 



do. 

Seeds.. 



do 

Flowers 

Seeds, pods. 



Seasons when 
eaten i 



Wi.... 

Sp, su, au, wi 

Au.... 

Sp, su, au 

Sp. 

Sp 

Au... 

Wi 

Su, au. 

Au, wi 

Sp-.. 

Su, au, wi 

Au 

Au 

Wi.. 

Su, wi-. 

Sp..-. 

Su--. 

Sp, su 

Wi 

Wi.sp- 

Sp... 

Sp.- 

Au, wi,sp 

Su, au, wi 

Wi 

Su, au-. 

Sp 

Wi 

Au 

Wi, sp, su 

Au, wi 

Au, wi 

Au 

Au, wi, sp 

Au 

Au 

Su 

Sp-. 

Sp 

Wi 

Sp 

Sp.. 

Sp, su 

Su.... 

Sp, wi, au 

Wi-.- 

Au, wi 

Su, au, wi 

Su 

Sp, su, au 

Wi 

Au, wi 

Sp 

Sp 

Sp, su... 



Source of 
data' 



St. 

St, sc. 

St. 

St. 

St. 

St. 

St. 

St. 

Si. 

Si, St. 

St. 

St. 
St. 
St. 

St. 
St. 
St, si. 

St. 

St. 

St. 
St. 

St. 
St, si. 

St, si. 
St, sc. 
St. 
St, si. 



St. 
St. 
Si. 
St, sc, si. 

St, sc, si. 
St. 

St, si. 
St, sc. 

St. 
St. 
St. 
St. 
St. 
St. 

St. 

St. 

St, sc. 
St. 

St, si. 

St. 

St, sc, si. 



St, sc. 
St. 
St, sc. 

St, si. 
St, sc. 

St. 
Si. 
St, sc. 



I Abbreviations of seasons: Sp, spring; Su, summer; Au, autumn; and Wi, winter. 

' Abbreviations of sources: St, stomach examination; Sc, scat examination; and Si, sight record. 

303807° — 41 3 



28 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 
Table 10. — Some insect foods (68) of Attwater's prairie chicken 



Name 



Araneida: 

Spider (Lycosidae) 

Spider (undetermined) 

Orthoptera: 

Grasshopper ( C jrrtacanthacrinae) 

Pigmy locust (Acrydinae) 

Grasshopper {Syrbula) 

Grasshopper (Oedipodinae) 

Western grasshopper (Melanoplus ciner- 

eus). 
Green grasshopper (Chortophaga viridi- 
fasciata) . 

Grasshopper (Oedipodinae) 

Grasshopper (Schistocerca americana) 

Grasshopper (Saliatoria) 

Meadow grasshopper (Conocephalus) 

Long-horned grasshopper (Tettigoniidae) . 

Hemiptera: 

Shield bug (Pentatomidae) 

Bug (undetermined Hemiptera).. 

Stinkbug (Euschisius) 

Homoptera: 

Leafhopper (Cicadellidae) 

Lantern fly (Fulgoridae) 

Soft scale (Leucanium) 

Coleoptera: 

Weevil (Oraphorhinus vadosus) 

Weevil (Lixus) 

Weevil (Thecesternus humeralis) 

Billbug (Sphenophorus minimus) 

Billbug (Sphenophorus bartramiae) 

Billbug (Sphenophorus germari) 

Billbug (Sphenophorus) 

Weevil (Paris) 

Weevil (Hyperodes) - 

Rice-water weevil (Lissorhoptrus simplex) - 

Weevil (Pachyphanes) 

Weevil (Anthonomus fulvus) 

Snout beetle (Curculionidae) 

Weevil (Apian) 

Scarred snout beetle ( Tanymecus lacaena) . 
Scarred snout beetle (Eudiagogus pulcher) 
Scarred snout beetle (Compsus auricepha- 
lus). 

Leaf beetle (Phaedon viridis) 

Leaf beetle ( Cryptocephalus venustus) 

Leaf beetle ( Cryptocephalus) 

Leaf beetle (Zygogramma disrupta) 

Leaf beetle (Oedionychis petaurista) 

Leaf beetle (Metacroma ustum) _. 

Leaf beetle (Disonycha) 

Leaf beetle (Ghrysomelidae) 

Leaf beetle (Calligrapha similis) 

Leaf beetle (Oraphops pubescens) 

12-spotted cucumber beetle (Diabrotica 
duodecimpunctata) . 

May beetle (Phyllophaga) 

May beetle (Scarabaeidae) 

Leaf chafer (Anomala ludotnciana) 

Dung beetle (Aphodius sp.) 

Ground beetle (Triplectrus) 

Ground beetle (Eumolops) 

Ground beetle (Carabidae) 

Ground beetle (Chlaenius) 

Darkling beetle (Tenebrionidae) 

Lepidoptera: 

Moths, butterflies, and skippers (3 spe- 
cies) . 
Salt-marsh caterpillar (Estigmene acraea).- 

Diptera: 

Gall gnat (Cecidomyiidae)... 

Robber fly (Asilus) 

Hymenoptera: 

Gall fly (Cynipidae) 

Chalcid fly (Chalcidae)... 

Paper wasp (Polistes) 

Ant (Odontomachus haemotodes) 

Ant (Pheidole sp) 

Fire ant (Solenopsis sp.) 



Form eaten 



Adult.. 
do- 



do 

Adult, larva. 

do 

do 

do 



-do. 



.do. 



do_ 

do 

do 

Adult, larva, egg. 



Adult 

Adult, eggs- 
Adult. , 



-do- 
.do-. 
-do- 

-do- 
-do- 
-do- 



-do- 
-do. 
.do. 
-do. 
.do. 
-do- 
.do. 
-do. 
.do. 
.do. 
.do. 



.do. 
.do. 
.do. 



.do. 



.do. 
.do. 
.do. 
.do. 
.do. 



-do. 
.do. 
.do. 
.do. 
.do. 



.do. 
.do. 
.do. 
-do- 



-do. 
.do. 
.do. 
.do. 
.do. 



Adult, larva. 
....do 



Larva. 
Adult. 



Adult, eggs.- 

Adult 

Adult, pupa cases. 
Adult 

do 



Seasons when 
eaten i 



Au-... 
Su, au- 



Sp, su 

Sp, su, au. 

Au :.. 

Au 

Su, au 



Su. 



.do- 



Su 

Su 

Su 

Sp, su, au. 
Su, au 



Sp- 
Su. 



Au, wi, sp- 
Sp, su, wi.. 
Au 



Wi, sp- 
Su, wi. 
Wi 



Sp, au. 
Sp, au. 
Su, wi- 
Sp, su.. 
Sp-.... 

Sp 

Sp_.... 
Sp.--.. 
Sp, su.. 

Wi 

Wi 

Au 

Sp..... 



Wi 

Su, au 

Su 

Su, au 

Au 

Au 

Sp, su, wi. 
Sp, su, au. 

Wi 

Wi 

Wi 



Sp 

Su, au 

Au 

Sp 

Au, wi 

Wi 

Sp, su. au. 
Su--..— . 
Au... 



Su, au. 
Su, au. 



Sp. 
Au. 



Sp..... 

Su 

Su, wi. 

Wi 

Su 

Su 



Source of 
data' 



St. 
St. 

St, sc. 
St, sc. 
St. 
St. 
St, sc. 

St. 

St, sc. 
St. 
St. 
St. 
St, sc. 

St. 
St. 
St, sc. 

St. 
St. 
St, sc. 

St. 

St. 

St. 

St. 

St, sc. 

St, sc. 

St, sc. 

St. 

St. 

St. 

St. 

St. 

St, sc. 

St. 

St. 

St, sc. 

St. 

St. 

St, sc. 

Sc. 

St, sc. 

St. 

St. 

St, sc. 

St, sc. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St, sc. 

Sc. 

Sc. 

Sc. 

Sc. 

St. 
St. 

St. 
Sc. 

St. 
St. 
St. 
St. 



' See footnote 1, table 9. 
' See footnote 2, table 9. 



ATTWATER'S PRAIRIE CHICKEN 29 

Native plants are the most important source of food for the 
prairie chicken. Rated according to frequency of occurrence in 
stomachs and scats, gross bulk, and periods of availability, ruellia 
{Ruellia) appears to be by far the most important single food. It 
occurred in 13 of the 18 stomachs and made up almost 27 percent 
of all the material eaten. Stargrass (^2/^6)a?^s), bedstraw {Galium)^ 
doveweed (C^roi^o^i), perennial ragweed {Ambrosia psilostachy a) also 
were eaten freely through long seasons. Practically all the impor- 
tant food plants utilized by the prairie chicken grow naturally in 
pastures that are moderately grazed. Corn was the only cultivated 
grain found, and the small quantity present was probably waste. 
It is known, however, that prairie chickens are fond of certain crops, 
especially peanuts, hegari, and ripened rice. The birds frequently 
congregate in peanut patches, particularly after the harvest, and 
scratch for the waste pods. They also use conveniently situated 
hegari fields extensively in summer, but the good shade in such 
areas is probably as attractive as the grain. Prairie chickens also 
range into rice fields after the crop is cut and shocked, and they 
sometimes feed on the grain in the shock as well as on that so freely 
wasted on the ground (pi. 7). The rice taken from shocks usually 
is not objectionable, although L. D. Roberts, Eagle Lake, Tex., 
reports that he saw approximately 1,500 of the birds feeding in a 
single field of about 500 acres in the Egypt section, Wliarton County, 
in September 1920. By scratching, the prairie chickens loosen the 
shocks, thus allowing moisture to seep in, and this causes some com- 
plaint. A large increase of prairie chickens might conceivably bring 
on control problems in certain areas. The difficulties would prob- 
ably not be serious, however, because the birds could easily be 
frightened by shotgun fire or by other disturbances, and they quickly 
desert areas of potential danger. 

Among insect foods of Attwater's prairie chicken, 11 grasshoppers 
(6 identified to genus or species) are especially prominent; 32 
beetles (identified to genus or species, including 16 weevils) also 
are important. The vast majority (50 of 65) of the insects eaten 
by prairie chickens are kinds neutral (25) or harmful (25) to 
agriculture. Field observations, and reports of cooperators, show 
that prairie chickens eat in large quantities the moths of the cotton 
leaf worm {Alabafnu argillacea), one of the worst insect pests in 
the coastal area. Under ordinary conditions, the food habits of 
Attwater's prairie chicken, considering both insect and plant con- 
sumption, are such as to make it one of the most valuable birds of 
farm and ranse. 



30 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

HABITAT REQUIREMENTS 
KIND OF HABITAT BEST SUITED 

The coastal prairie grassland is the real home of Attwater's 
prairie chicken, particularly in areas characterized by diversity of 
vegetation (pi. 8). Woodland, brushland, and cultivated land each 
furnish some food and cover at certain times and under certain 
conditions, but use of these types is optional with the prairie chicken, 
not vital. These secondary habitats are frequented mostly when food 
and cover are at the annual peak, as in September and October, 
but are little used at times of seasonal scarcity, as in December, 
January, February, and early in March. Wooded, cultivated, and 
brushy areas, individually or in combination, contribute little or 
nothing as courtship grounds and nesting cover. Properly managed 
grassland (pi. 9), however, satisfies every known requirement of 
Attwater's prairie chicken, and management, therefore, should be 
directed toward improvement of these areas. 

CHARACTER AND DENSITY OF VEGETATION 

Optimum food and cover conditions seemingly are approached 
when the prairie vegetation is varied in species, interspersion, and 
density. The plant life of well-populated areas includes a variety 
of grasses, sedges, rushes, and legumes, and tall weeds or their cover 
equivalent in the form of scattered clumps of myrtle or live-oak 
brush. The combination and density of the plants in the most 
favored places invariably is such as to provide cover in all degrees 
and well distributed. 

Light cover serves (1) exclusively for the courtship performance, 
(2) for feeding at all seasons, and (3) for a resort when dew is 
heavy or after rains. Light to medium heavy cover is used (1) for 
roosting, especially on gentle slopes, (2) by chicks under 5 weeks old, 
and (3) for feeding by adults throughout the year. Cover of a 
medium heavy to heavy character (pi. 9) is utilized (1) extensively 
for nesting, (2) as a loafing cover except during the hot sunmier 
months, and (3) as feeding grounds and escape cover in emergencies. 
Heavy cover (pi. 9) is essential (1) for shade in summer, (2) for 
protection against unfavorable weather and predators at other sea- 
sons, and (3) as a source of food, especially in fall. 

TOPOGRAPHY 

Eichness and variety in the vegetation are promoted by even slight 
variations in topography and soil (pi. 8). Consequently, the best 
natural range for Attwater's prairie chicken comprises country in 
which knolls, ridges, or hog wallows, are frequent. Further, knolls 



North American Fauna 57. Fish and WildUfe Service 





MMH 


^^■MMBB 


m^"' '••"^'-^ 




.-»ii~.^.i*.. ■■ 


-m 




'■■.%-■.■ : 


J 



Above, Diversified cover^ — exceliont i)rairie chicken range; Colorado County, 
Tex., approximately 7 miles northeast of Eagle Lake, September 4, 1936. 
Below, Diversity of topography and vegetation; Austin County, Tex., approxi- 
mately 6 miles northeast of Bellville, June 13, 1936. (Photos by V. W. Leh- 
mann.) 



North American Fauna 57, Fish and Wildlife Service 



PLATE 9 





Above, Medium-heavy to heavy cover — excellent food-cover conditions in a 
moderately grazed pasture; Colorado County, Tex., approximately 8 miles 
north of Eagle Lake, December 21, 1936. Below, Heavy cover, mostly myrtle 
brush, near stream — excellent summer range; Austin County, Tex., approxi- 
mately 4 miles east of Bellville, July 14, 1936. (Photos by V. W. Lehmann.) 



ATTWATER'S PRAIRIE CHICKEN 31 

and ridges are least likely to be inundated in times of flood and they 
afford the birds better opportunity of eluding their natural enemies 
and man. 

WATER 

The balanced prairie chicken habitat should offer a generous supply 
of surface water throughout the year. Although Attwater's prairie 
chickens may not be dependent on free water for survival during 
normal years (see p. 23), it has been established that their favorite 
summer range is rather well watered. During unusually dry years 
such as occurred in Refugio County in 1917, surface water may be 
an absolute necessity. Also, through its effects on vegetation and 
insect life, water is necessary for the maintenance of optimum cover 
and food conditions. The water supply of prairie chicken areas 
apparently is about optimum when permanent sources are available 
throughout the range at intervals not greater than a mile. 

Briefly, then, habitat conditions for Attwater's prairie chickens 
seemingly approach the ideal in grassland area when (1) the vegeta- 
tion is diversified and native grasses, sedges, legumes, and small and 
large weeds, or their equivalent in the form of brush or dwarfed trees, 
are present in such stands as to provide all densities of cover; (2) 
knolls, ridges, and hog wallows are frequent and the soils vary from 
loose sand to tight clay or silt; and (3) permanent sources of surface 
water are available not more than a mile apart. 

SEASONS OF SCARCITY 

In evaluating the suitability of an area for Attwater's prairie chick- 
ens it is to be kept in mind that its productivity or carrying capacity 
is not determined by conditions during the best season in a good year. 
Rather, as Taylor (1934) states, conditions that prevail during the 
most critical season of the year and in the most extreme year in a 
series of years determine carrying capacity. In the coastal country of 
Texas the season of scarity, or the period when food and cover are at 
a minimum, normally is from December through early March. The 
most critical years are those of heavy rainfall in May. 

LIMITING FACTORS 

Factors that have contributed to the decrease of prairie chickens 
in Texas may be classed roughly as (1) natural, including unfavor- 
able weather, predators, and disease; and (2) artificial, including 
cultivation, heavy grazing, burning, and overshooting. It might 
be more accurate to class limiting factors as those brought about by 
man, directly or indirectly. Although it is not generally appre- 
ciated, the decrease of prairie chickens in coastal Texas corresponds 



32 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

with the spread of civilization. Prior to the coming of white men, 
the number of birds probably was well maintained, but there was 
a decrease as the country was developed. Attwater's prairie chicken 
will become extinct unless man ceases to exploit the soil, water, and 
other natural resources of its range. 

NATURAL FACTORS 

Rainfall During the Nesting Season 

Prairie chickens in Texas evidently suffer greatly at times from 
extremes of weather. Heavy precipitation during the nesting and 
brooding season (March through June) appears to be an especially 
serious hazard, as indicated by the studies of Waddell and others in 
Colorado, Austin, and AVliarton Counties. From 1925 through 1937 
Waddell estimated the size of the annual crop of young prairie 
chickens on the basis of the number of birds, both young and old 
(1) observed on almost daily trips through their range, (2) seen by 
reliable resident observers, (3) bagged by hunters, and (4) counted an- 
nually on the courtship grounds in spring. From his studies he con- 
cluded that crops of young prairie chickens were (1) good in spring 
months when rainfall was below average, (2) fair to good when 
rainfall was average or only slightly above average, and (3) poor, 
very few young being reared, when the nesting season was abnormally 
wet. 

Waddell's impressions as to the correlation between the amount of 
precipitation in spring and the size of the annual crop of chickens 
were tested rather thoroughly in 1936 and again in 1937. In August 
1936, after a reconnaissance made v/ith car and dog (see p. 52) over 
approximately 25,000 acres of territory in Colorado and Austin 
Counties, it was estimated that the annual increase was less than 10 
percent. Rainfall there was below average in March, April, and 
June 1936, but it exceeded 10 inches, or approximately twice the aver- 
age, in May, as shown by the records of the Weather Bureau at 
Columbus, situated centrally in that area. In 1937, when records 
of this station showed that rainfall was 2 inches or more below 
average in April, May, and June, rope counts made of 3,450 acres 
both before and after the breeding season revealed a 95-percent in- 
crease, supporting Waddell's estimate that the increase was good 
in a dry season. 

In table 11, p. 33, Waddell's estimates of the favorableness of the 
years from 1925 through 1937 for prairie chicken reproduction are 
presented together with precipitation records of the Columbus 
Weather Bureau Station for March, April, May, and June in those 
years. 



ATTWATER'S PRAIRIE CHICKEN 



33 



Table 11.— Reproductive yield of Attwater's prairie chicken in relation to spring 
rainfall in inches ^ in the Colorado County area ^ 





Estimated 
yield 


March 


April 


May 


June 


Year 


Precip- 
itation 


Depart- 
ure 
from 

normal 


Precip- 
itation 


Depart- 
ure 
from 

normal 


Precip- 
itation 


Depart- 
ure 
from 

normal 


Precip- 
itation 


Depart- 
ure 
from 

normal 


1925 

1926 


Good 

Fair . . 


0.33 
11.54 
3.49 
1.42 
4.54 
2.34 
3.84 
3.63 
2.36 
3.91 
3.72 
1.23 
6.01 


-2.50 

-8.71 

.66 

-1.41 

1.71 

-.49 

1.01 

.80 

-.47 

1.08 

.89 

-1.60 

3.15 


0.99 
7.86 
4.00 
3.76 
2.58 

.48 
1.43 
2.19 
1.43 
4.28 
4.58 
3.48 

.52 


-2.74 

4.13 

.27 

.03 

-1.15 

-3.25 

-2.30 

-1.54 

-2.30 

.55 

.85 

-.25 

-3.21 


2.87 
4.10 
1.24 
2.00 

16.12 
3.11 
1.98 
.66 
3.67 
1.90 
9.21 

10.65 
.47 


-1.51 

-.28 

-3.14 

-2.38 

11.74 

1.27 

-2.40 

-3.72 

-.71 

-2.48 

4.83 

6.27 

-3.91 


1.06 
3.37 
6.43 

8.52 
.99 
.89 
.90 

3.68 

1.40 
.22 

2.48 
.79 

1.37 


-2.12 
19 


1927 

1928 

1929 - 

1930 


Good 

do 

Poor 

Fair 


3.25 

5.34 

-2.19 

— 2 29 


1931 


Good 

do 

Fair 


— 2.28 


1932 

1933 


.50 
-1.78 


1934 


Good- - 

Poor 

___. do 


— 2.96 


1935 


-.70 


1936 


— 2.39 


1937 


Good 


-1.81 



1 Records of U. S. Weather Bureau Station, Columbus, Colorado County. 

' Colorado County, north central Wharton County, southwestern Austin Coimty. 

Waddell found good crops of young birds in the Eagle Lake area 
in 1925, 1927, 1928, 1931, 1932, 1934, and 1937, years when rainfall 
in May was 1.5 inches or more below average. Fair crops of young 
prairie chickens were thought to have been reared in 1926, 1930, 
and 1933, when rainfall in May was approximately average (0.28 
below in 1926) to only slightly above (1.27 above in 1930). Poor 
crops were matured in 1929, 1935, and 1936, when May precipitation 
was appreciably above (approximately twice) the average for that 
month. Unusually heavy or light precipitation in March, April, or 
June evidently liad little influence on the broods of young, for good 
crops were recorded in 1927, when rainfall was decidedly above 
average in June, and a poor crop is known to have occurred in 1936, 
w^hen rainfall was below average in all months of the nesting season 
except May. The records at hand suggest, therefore, that the rain- 
fall in May is a fairly satisfactory index of the suitability of the 
year for the reproduction of Attwater's prairie chicken under natural 
conditions. Good crops usually result when the rainfall in May is 
1.5 inches or so below average ; fair crops are probable when it is 
approximately average or only slightly above; and poor crops appear 
almost a certainty when the rainfall for that month is decidedly 
above average. 

Rainfall in May is of greater significance than that in any other 
month, as the 1937 and 1938 nesting studies showed that most of the 
chicks hatch in May. Those hatched in April do not yet have a 
serviceable covering of feathers by May and, consequently, are almost 
as vulnerable to the rains as are birds hatched in that month. Nests 
flooded in March and April may be rebuilt, for the booming season 
is still in full swing, but nests flooded after May 1 are seldom re- 



34 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

established because the mating season is then nearly over. May, then, 
is the climax, or peak month, of the breeding season, and rainfall 
then is of greater significance than at any other period. 

The nature of rains in May may be a factor modifying the use of 
precipitation records for that month as indices of the number of 
chicks produced, as short, heavy downpours may be more serious than 
slow steady rains. This, however, is not known to be true. Fre- 
quently recurring light rains may be as serious as heavy ones be- 
cause persistent damp conditions result in heavy juvenile mortality 
from chilling. Stoddard (1931: 39, 202) shows that wet spring 
months are favorable for hatching but not for rearing bobwhites. 
Percolation and drainage are slow in the heavy coastal prairie soil, 
and surface moisture accumulates from persistent light rains as surely 
as from brief heavy ones ; the amount rather than the severity of the 
rain seems to rule. 

While it is realized that annual precipitation, drainage, cover, and 
other environmental conditions in Colorado County are not identical 
with those obtaining throughout the coastal prairie chicken country, 
a marked similarity does, nevertheless, exist. Rainfall is moderately 
heavy, 39 inches annually, at Columbus, Colorado County, and it is 
also generous throughout the bird's range. Average annual precipi- 
tation varies from 49.35 inches at Beaumont, Jefferson County, to 
33.69 inches at Austwell, Refugio County, at about the eastern and 
western limits, respectively, of the subspecies. Rainfall during May 
at Columbus (average, 4.38 inches) is heavier than in any other 
month. May is the wettest month in Jackson, Goliad, Lavaca, and 
Harris Counties as well. Heavy or persistent rains transform tre- 
mendous areas in Colorado Coimty into veritable lakes ranging from 
a few inches to several feet in depth; rains produce similar results 
throughout the coastal region. It appears justifiable, therefore, to 
assume that rainfall in May is the key to prairie chicken reproduc- 
tion throughout coastal Texas (fig. 3) . 

Of every 5 years in a given locality, apparently 2 are favorable 
for nesting, 2 fair to poor, and 1 bad, as determined by rainfall in 
May. Conditions are never uniform in the chicken country ag a 
whole because there is variation between counties and even between 
parts of the same county. Records of the Weather Bureau for May 
1935 show, for example, that rainfall at Galveston, Galveston County, 
was favorable (2.71 inches below average) ; at Houston, Harris 
County, fair (only 0.20 inch below) ; and that at Columbus, Colorado 
County, poor, being approximately twice average (4.83 inches above) . 
During 1926 in Brazoria County conditions were good at Alvin, fair 
at Angleton and Freeport, and poor at Brazoria. In 1932 conditions 
were good at Angleton, fair at Freeport, and poor at Alvin. Though 
man cannot regulate rainfall to promote prairie chicken welfare 



I 57. Fith «nd WUdJife Strvice 




LEGEND 

Rainfall 1 .50 inches or more below average _____ 

Rainfall 1 .49 below average to 1 .99 above average 

Ramfall 2 inchea or more above average, but less than twice aver 
Rainfall twice average or more 

Compilations based on records of average annual May rainfall i 
supplied by the Climatological Division. U. S. Weather Bure 
Records missing or unsatisfactory 



-I — i(G°°a) 

Erg (Fair) 

. ^ (Bad) 



ich individual station 



CZ] 



Rainfall conditions in May in the range of Attwatcr's prairie chicken in Texas, in the 66 years I87I to 1936. 
indicating the probable frequency of good and other reproductive years for the birds 



ATTWATER'S PRAIRIE CHICKEN 35 

at nesting and brooding time, in many case3 he can regulate pasture 
burning and grazing to provide adequate nesting cover in the best- 
drained parts of the land. Also, he can consult weather records 
before setting open seasons and bag limits, which should not be 
uniformly applied but adjusted to local conditions to preserve the 
birds. 

Floods 

Flood conditions are often produced by heavy rains in the over- 
grazed and overfarmed sections in the upper part of the State. 
Heavily burdened streams carrying flood crests from the upper coun- 
try sometimes spill over their low banks and spread their silt-laden 
waters over thousands of acres of prairie chicken range. This oc- 
curred in the Rock Island-Garwood section (Colorado County) in 
June 1936, when the prairie chicken population of that section was 
extirpated. Floods evidently are a constant menace to birds near 
major streams. 

Dbought 

Extreme drought seriously affects prairie chickens, especially dur- 
ing the hot summer months. G. P. Ferguson, State game warden, 
and fence riders on the M. O'Conner ranch, Refugio County, found 
many dead birds in the especially dry suimner of 1917 and saw others 
too weak to fly. Drought reduces food supplies for both present and 
future use. Large cracks that form in black soil in dry weather pos- 
sibly trap some young birds, according to the observations of Gross 
(Bent 1932: 253). Birds weakened by excessive heat, and possibly 
also by a shortage of food, are especially vulnerable to disease, pred- 
ators, adverse weather, and other hazards. 

HXJBBICANES 

Tropical hurricanes sometimes produce flood conditions in prairie 
chicken country 20 miles or more from the Gulf. In 1917 a storm 
backed salt water over the greater part of the Pipkin ranch in the 
Big Hill area in Jefferson County and drowned livestock by the 
hundreds. That it evidently destroyed many prairie chickens as 
well was indicated by their exceeding scarcity for 15 years afterwards. 

TTatt. 

Heavy hail storms destroy many Attwater's prairie chickens, es- 
pecially in areas where heavy protective cover is lacking. After a 
storm in May 1934, J, O. Linney, Guy Ferguson, and fence riders on 
the Salt Creek ranch, Refugio County, saw about 150 dead or crippled 
chickens. 



36 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

Local Storms 

Local storms, especially those that commonly occur in fall, kill 
turkeys and other domestic fowls and prairie chickens and other game 
birds, as reported by Marcus Shindler, Ed Koy, and other resident 
land-owners in the northeastern part of Colorado County. 

Disease 

Gross (1930a: 39), and Stoddard, Curtis, Lews, Terrel, and others 
(Leopold 1931: 182-183), recorded incidents strongly suggesting that 
disease and parasites probably were important controlling factors on 
the abundance of the greater prairie chicken of the Northern States. 
Records at hand do not show that, in the past, disease has been a factor 
of importance limiting the numbers of Attwater's prairie chicken in 
Texas. The observations, mentioned above, made by G. P. Ferguson 
on the M. O'Conner ranch furnished the only known evidence even 
faintly suggesting an outbreak of disease. In that instance, however, 
it is probable that mortality, if really due to disease or parasites, was 
an indirect result of prolonged drought. No evidence of disease or 
heavy parasitism was found in autopsies made on 13 prairie chickens, 
and no evidence of any unhealthful condition was observed among 
hundreds of birds in the field. Prairie chickens are doubtless sus- 
ceptible, however, to ailments of domestic poultry. An outbreak of 
blackhead disease, probably contracted from domestic turkeys, is con- 
sidered by Gross (Bent 1932: 268) as a major factor in the extermina- 
tion of the heath-hen. Turkeys and other poultry, therefore, probably 
are unhealthful influences on a prairie chicken range. 

Spkeab of Woody Vegetation 

The encroachment of mesquite, live oak, various acacias, and other 
kinds of brush onto open prairie land has been an extremely impor- 
tant factor in reducing the range and doubtless the numbers of Att- 
water's prairie chickens in Refugio and other counties to the south 
and west. Within the memory of living men extensive prairies have 
been transformed into brush jungles. Specific factors that have in- 
fluenced the rapid vegetational changes in the southwestern brush 
country are imperfectly understood. Factors probably of importance 
in enabling woody plants to replace the native grassland flora have 
been overgrazing, especially during drought years; the mechanical 
planting of tree seeds by cattle and horses, because livestock eat large 
quantities of mesquite and other beans, the seeds of which pass through 
the digestive tract and are distributed or planted by the droppings ; 
the elimination of burning, previously mentioned by Bray (1901: 
288-290) and Tharp (1926: 71) ; and the lowering of the water table. 
Be that as it may, hundreds of thousands of acres of what was once 



ATTWATER'S PRAIRIE CHICKEN 



37 



tall-grass prairie are now brushland, and prairie chickens are gone 
from these areas. 

Pkedation 



NESTS 



Natural enemies consume some of the eggs, young, and adults of 
Attwater's prairie chicken. The extent of predation on nests and the 
identity of other factors responsible for nest loss in the Eagle Lake 
area are given in tables 12 and 13. 

Table 12. — Fate of nests, Eagle Lake, Colorado, 1937 



Nest 
No. 


Pasture 


Date 
found 


Date 

destroyed 

or 
hatched 


Probable cause of destruction 


1 ... 


Everett 


Apr. 7 

Apr. 8 
Apr. 12 

---do...- 
Apr. 13 
Apr. 21 

-...do..-. 

---do.... 
Apr. 27 
Apr. 29 
May 1 

May 11 
June 1 


Apr. 22 

Apr. 4 3 
Apr. 7 
Apr. 13 
May 17 
Apr. 15 
Apr. 21 
Apr. 18 
May 4 
May 15 
May 2 

Apr. 6 
June 2 

or 
June 3 


Man— nest deserted after entrance was widened 
by a farmer. 


21 


do 


31 


Wintermann .- 


Opossum or skunk. 

Skunk. 

Hatched successfully. 

Skunk. 


i 

6.. - 


do 

Sklar-Marcella 

Wintermann 


61 


71 

81. 

9 


do 

do 

Duncan... 


Do. 
Deserted, cause unknown. 
Hatched successfully. 

Do 


10 


Everett . 


H 


Willis 


Man— nest deserted after farmer plowed territory- 
nearby and revisited nest frequently. 
Opossum. 
Hatched successfully. 


12».. 

13 . - 


Sklar-Marcella 

do 







1 Nest destroyed when found. 

' Estimated in case of nests destroyed when found. 

» Indicated by circumstantial evidence at the nest. 

Table 13. — Fate of nests, Eagle Lake, Colorado County, Tex. (1938) 



Nest No. 


Pasture 


Date 
found 


Date de- 
stroyed 

or 
hatched 

May 3 
Apr. 23 
Apr. 29 
May 3 
May 11 
June 21 


Probable cause of 
destruction i 


14 


Sen 


Apr. 13 

Apr. 18 

do 




15 


Thomas 


House cat 


16 


do 


Hatched successfully. 


17 


do 


Apr. 29 
Apr. 20 
June 3 


18 


Everett 




19 


.... do 


Hatched successfully. 







1 Indicated by circumstantial evidence at nest. 

Of 19 prairie chicken nests studied in 1937 and 1938, 6 (31.5 
percent) were successful, and 13 (68.4 percent) were lost. In 1937 
8 of 13 nests studied were destroyed before the clutches were com- 
plete, showing that the laying period may be the one of heaviest 
nest loss. This might be expected, as the eggs are covered only about 
an hour or so each day during that time. This loss is somewhat 
compensated, however, by renesting (see p. 15). Opossums and 
skunks destroyed 6 nests — more than any other agency. Of the 6, 



38 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

however, 4 were in a pasture where unregulated fire had restricted 
good nesting cover to 2 small unburned areas about 3 and 10 acres 
in size. Fur animals as well as nesting chickens were unnaturally 
concentrated in these unburned plots; dens containing young were 
100 yards or less from each of the nests destroyed. Excessive pas- 
ture burning appeared to be the primary cause of the heavy nest 
loss ; predation by fur animals being merely an effect, the agency of 
destruction that was inevitable after the burning. 

Field evidence showed that a red wolf killed a female prairie 
chicken and destroyed her nest; a feral house cat devoured the 
eggs from another nest (pi. 10). It is surprising that dogs did 
not figure as predators on the nests and that house cats did not 
take an even greater number. Wandering dogs, usually in groups of 
three to five, were not uncommon on Colorado County prairies; L. 
A. Burchfield, a trapper who worked for the former Bureau of 
Biological Survey in Colorado County in 1937, and Waddell found 
that dogs did much of the damage for which the few red wolves, 
now largely extirpated in the area, were blamed. Heavy predation 
on a flock of domestic turkeys, supposedly by wolves, stopped imme- 
diately when a hound, which frequently hunted on its own initiative, 
was killed after having been caught in a trap set for the alleged 
wolves. Feral house cats on Colorado County prairies probably 
outnumber skunks, opossums, minks, or any other fur animals. Cot- 
ton rats and other rodents were common near several nests but took 
no eggs. Neither did racers, chicken snakes, king snakes, or other 
reptiles frequently noted after May 1 in both 1937 and 1938. 

Three nests were abandoned, desertion of two of these, possibly 
all three, being caused by man. Nesting! prairie chickens seem 
especially sensitive to interference, and they should not be dis- 
turbed by persons making repeated visits. Of six nests under obser- 
vation in 1938, floods destroyed two, and accumulated water from 
heavy rains came within V^ feet of a third (nest 16). The following 
excerpt from the writer's field notes of May 3, 1938, emphasizes the 
importance of floods : 

The prairie has been transformed into a miniature ocean dotted by tiny 
islands that previously had been the tops of knolls and ridges. On these 
islands sit wet and bedraggled prairie chickens and other birds that seem as 
confused and astounded as I by the sudden change in their environment. About 
a 5-inch depth of water covers the sites of nests 14 and 17, and former 
nest 15. Nest 16 has escaped by a hair's breadth, but the lining is very soggy. 
Problems due to hawks, skunks, and other predators seem so petty when exces- 
sive rain destroys virtually everything at a single stroke. 



Although predators doubtless exert great pressure on the popula- 
tion of young prairie chickens in some areas, especially because the 



North American Fauna 57, Fish and Wildlife Service 



Plate 10 





; 646862 



AboDc, Shells of eggs at prairie chicken nest destroyed by house cat; Colorado 
County, Tex., approximately 5 miles north of Eagle Lake, April 23, 1938. 
(Photo by Texas Game, Fish, and Oyster Commission; E. P. Haddon.) Below, 
Freshly killed prairie chicken recovered from a ferruginous rough-legged hawk; 
Colorado County, Tex., approximately 6 miles north of Eagle Lake, April 7, 
1937. (Photo by V. W. Lehmann.) 



North American Fauna 57, Fish and Wildlife Service 



PLATE 1 1 





B49777A, £60058 



Above, Native bluestem prairie — well populated b}' prairie chickens: Colorado 
County, Tex., 6 miles northeast of Eagle Lake, December 21, 1936. Below, 
Prairie after plowing for rice — deserted by prairie chickens; Colorado County, 
Tex., approximately 5 miles north of Eagle Lake, March 7, 1938. (Photos 
by V. W. Lehmann.) 



ATTWATER'S PRAIRIE CHICKEN 39 

loose formation of the brood (see p. 19) and straying apparently 
induce mortality from this cause, definite information was difficult 
to obtain. 

A female Krider's hawk caught a third-grown prairie chicken on 
May 24, 1937. From then on until June 9, when the male was col- 
lected, this hawk, assisted by her mate, hunted a section containing 
six broods. Most migrant raptors (roughlegs, redtails, and marsh 
and duck hawks) had left Colorado County prior to May 1, 1937, and 
April 15, 1938, before many young had hatched, and the resident 
species (red-shouldered, Cooper's, Sennett's white- tailed, and Krider's 
hawks) confined their activities largely to wooded areas. Because 
cover is dense in summer, and hawks are then uncommon, probably 
few young prairie chickens are taken in normal years. 

House cats with freshly killed young prairie chickens were noted 
twice in 1937 and were seen stalking broods on three other occasions. 
Because of their numbers and predilections, house cats are thought 
to be exceedingly destructive. 

ADULTS 

Prairie chickens on the courtship grounds seemed more intent 
on mating than on self-preservation ; consequently, losses from preda- 
tion were probably heaviest at mating time. In Colorado County, 
during most of the 1937 and 1938 courtship seasons the abundant 
hawks harassed the prairie chickens persistently, sometimes with 
success. On April 8, 1937, 3 duck hawks, 7 marsh hawks, 2 rough- 
legs, 3 Krider's hawks, and 2 bald eagles kept the chicken population 
(about 45 birds) of the Everett pasture (640 acres) constantly mov- 
ing. A freshly killed male prairie chicken (pi. 10) was taken from 
a ferruginous roughleg in that area on April 17. Marsh hawks, 
which Stoddard and others have found to be sometimes more bene- 
ficial than harmful to quail and other game, were especially an- 
noying to courting birds, no other factor interfering with their 
activities to so great an extent. Wlien a marsh hawk darted at 
one occupant of the booming ground, others generally cowered. The 
hawks pursued their intended victims for short distances, but soon 
returned and flushed others, or after dispersing the grouse, fre- 
quently alighted on the courtship grounds to await their return and 
resume the flushing tactics. On April 8, 1937, 4 marsh hawks con- 
centrated on a single courtship ground and harassed the 6 male 
occupants from 5 to 7 :30 p. m. Although no birds were killed, one 
lost many feathers when two hawks dived at it simultaneously. 

By flushing prairie chickens, marsh hawks render them vulnerable 
to more efficient winged enemies, as duck hawks, goshawks, and the 
like. Waddell has seen duck hawks catch adult chickens on at 
least two occasions. 



40 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

Mammals also take some of the birds on courtship areas. The 
stomach of a male house cat collected April 12, 1937, near a booming 
ground in the Everett pasture, Colorado County, contained the head, 
feet, and part of the breast of a freshly killed male prairie chicken. 
The remainder was found about 50 feet away. 

A red wolf was suspected of killing a female prairie chicken on 
the nest, and either red wolves or dogs took three others in Colorado 
County in April 1937. 

Only six instances of adult mortality were discovered that year, 
although intensive search for remains was made on foot and in cars 
over approximately 2,500 acres. In 1938, when none of the pastures 
were burned, no dead birds were found. 

Review of Natueai, Factoes 

Natural factors limit the abundance of prairie chickens by destroying 
eggs, young, and adults and by reducing favorable territory. During 
the breeding season floods, storms, hail, drought, and excessive or per- 
sistent rains are known to be locally serious, the rains in May being most 
damaging. Drought has been associated with the only reported out- 
break of disease that occurred in the Refugio area in 1917. The en- 
croachment of brush on prairie land has transformed thousands of acres 
of what was once good prairie chicken range (pi. 11) into an unfavorable 
habitat. Although some predators harass the birds throughout the 
year, their effects are probably most serious at mating and nesting 
time. Natural mortality from climate and predators is severe in 
inferior or isolated cover. 

The serious effects of natural factors are in every case either brought 
about or intensified by man's generally unwise treatment of natural 
factors. All except feral house cats and predatory dogs were operat- 
ing against the prairie chickens, apparently without disastrous results, 
before the environment was radically modified by man. Since the 
unfavorable influences of natural agencies are due chiefly to man, it 
is encouraging to know that it is within his power and often decidedly 
advantageous to him so to modify his actions as to improve existing 
conditions and promote the welfare of the prairie chickens as well as 
his own. 

ARTIFICIAL FACTORS 

Agriculture 

Much of the best prairie chicken range has been recently appro- 
priated for agricultural uses. More than 2,000,000 acres (table 14) 
were cultivated in 1936. In addition, thousands of acres of sod are 
plowed annually, with the extension of agriculture, especially rice 
farming. The acreage yearly planted to rice in coastal Texas in- 



ATTWATER'S PRAIRIE CHICKEN 



41 



creased from approximately 174,500 acres in 1922 to more than 196,500 
acres in 1937.^ This latter acreage represents only a small part of the 
area actually depleted: rice farming has ruined more than 84,000 
acres for the birds in Colorado County (pi. 11) alone, and probably 
in excess of a million acres in the State as a whole. Rice is hard on 
the land and most areas devoted to it can be profitably cultivated 
during only about 1 year in 4, after which they must be left fallow for 
about 3 years to "sweeten." Weedy rice fields ostensibly provide satis- 
factory grouse range ; actually, however, they lack suitable courtship 
grounds and safe nesting cover, and, furthermore, the levees collect 
water that floods nests. Prairie chickens in fallow rice land ap- 
parently are doomed even though they are hunted lightly or not at 
all. According to Waddell, there were 10,000 of the birds on 30,000 
acres of the Egypt section, Wharton Comity, in 1924. Rice farming 
began there in 1925, and by 1937 all the 30,000 acres were either in 
cultivation or fallow. Hunting pressure was reduced annually after 
1925, and few, if any, birds were killed after 1935. In 1938, however, 
less than 150 prairie chickens remained. Prairie chicken decrease was 
also positively correlated with the expansion of rice farming in eastern 
Chambers and central Matagorda Counties. As additional acres of 
prairie are plowed, further decreases are certain to follow. 



Table 14. — Harvested and other crop land (1936) in counties partially or en- 
tirely loithin the probable former range of Attwater's prairie chicken in 
Texas ^ 



County 


Harvested 
crop land 


Other 
crop land 


Total 
crop land 


County 


Harvested 
crop land 


Other 
crop land 


Total 
crop land 


Aransas.. 


Acres 

2,484 
105. 396 

92, 247 
98,045 
34, 425 

130, 684 
16, 772 

93, 562 
153, 307 
176, 495 

19, 848 
64, 374 
100, 263 
82, 609 
44,205 


Acres 
1,772 
11,313 
20, 685 
17, 787 
12. 5S0 
32, 483 
5,727 
11,03.S 
30, 843 
41, 793 
3, 396 
12,711 
25, 031 
15, 114 
12, 386 


Acres 

4,256 
116, 709 
112,932 
115, 832 
47,005 
163, 167 
22,499 
104, 600 
184, 150 
218, 288 
23,244 
77, 085 
125, 294 
97, 723 
56, 591 


Kenedy 


Acres 

204 

28,639 

158, 604 

47,704 

.59, 714 

228, 609 

8, 245 

40, 147 

165, 691 

100, 300 

47, 986 

187, 555 

60, 981 


Acres 


Acres 
204 


Austin 




7,211 
10, 652 
12, 836 

21, 952 
62, 090 

1,334 
16, 183 
35, 769 
17,828 
10, 040 

22, 909 
10, 001 


35, 850 
169, 256 


Bee 




Brazoria 




Calhoun . 


Matagorda.. 

Nuoc^s. 


81, 666 
290 699 


Cameron 


Chambers 


Orange..' 


9 579 


Colorado -_ 




56, 330 
201 460 


DeWitt 


San Patricio 

Victoria 


Fort Bend 


118,' 128 


Galveston 


Waller 


58 026 


Goliad 




210 464 


Harris 


Willacy .. . 


70, 982 




Total 




2, 349, 095 


483,464 


2, 832, 559 





> Data from Texas Almanac and State Industrial Guide, pp. 231-236, The Dallas News, 1936. 

Pastubh Bubninq 

Unregulated prairie fires intentionally set or of accidental origin 
have been, and still are, common in coastal Texas in every month of 



^ Figures supplied by David WinternLinn, Relow Land Company, Eagle Lake, Tex., from 
data compiled by the Rice Milling Association. 



42 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

the year. In Colorado and Austin Counties, for example, approxi- 
mately 80 percent of the best prairie chicken country was burned over 
in 1936. A fire of accidental inception ran over about 3,000 acres of 
the 6,700 acre J. C. Anderson Estate ranch, Harris County, in May 
1937. The cover on about 3,000 acres of the best prairie chicken 
country in Matagorda County was intentionally burned in July 1937. 
Pasture burning is an annual event on the Pipkin ranch, Jefferson 
County, fires being started during first new moon after February 15. 
Areas that the first fires do not cover cleanly are subsequently treated, 
and burning generally continues well through the nesting season. 
Most ranchmen, however, complete pasture burning by March. 

The pastures are burned to remove old grass and encourage tender 
new growth more palatable to livestock. Fires usually are set when 
the grass is dry and the wind brisk, in order to finish the job quickly. 
The resulting fast, hot fires entirely denude areas except in low spots 
and deplete pastures of food, escape cover, and nesting sites. Prairie 
chickens and their natural enemies are crowded into unburned areas 
(pi. 12) and predation is undoubtedly intensified. During the breed- 
ing season fires destroy nests and probably many young birds as well ; 
no fewer than nine nests with charred eggs were found by Waddell in 
a 640-acre pasture burned in May 1936. Plant life recovers slowly 
in the absence of abundant rain; consequently, fires accentuate the 
results of drought. Altogether, fire is one of the most important 
factors limiting prairie chicken numbers in pastures. When burning 
is carried on as outlined under Management (pp. 53 to 54), however, 
the evils are greatly reduced or entirely eliminated, and benefits 
accrue to forage and soil as well. 

Overgrazing 

With the possible exception of Orange and Jefferson Counties, over- 
grazing is severe in most of coastal Texas from late in fall through 
early spring. In addition to reducing cover and food for prairie 
chickens (pi. 12), overgrazing probably also increases the vulnera- 
bility of the birds both to natural enemies and to man. In Colorado 
County from 1936 through 1938, for example, it was noted that marsh 
hawks and other raptors harried chickens more persistently in lightly 
vegetated pastures than in areas where heavy grassy cover was pres- 
ent. Waddell observed that hunters regularly kill a higher percent- 
age of known populations in areas where cover is light than where it 
is heavy. In Colorado County it has been found that the winter 
prairie chicken population of a pasture can be forecast with consider- 
able accuracy by observing the extent to which the area is grazed. 
Large winter populations are rare in pastures where cover is short. 



North American Fauna 57, Fish and Wildlife Service 



PLATE 12 






B49778; B60059 

Above, Excellent uiihurned cover at right of road; inferior burned cover at left; 
Colorado County, Tex., approximately 7 miles north of Eagle Lake, December 
22, 1936. Below, Scanty cover where there has been overgrazing; the shrub is 
Cherokee rose {Ro.sn laerignla); Colorado County, Tex., 6 miles north of Eagle 
Lake, March 7, 1938. (Photos by V. W. Lehmann.) 



ATTWATER'S PRAIRIE CHICKEN 43 

Aside from resulting unfavorably to prairie chickens, overgrazing 
in the gulf coastal country has been and is resulting in (1) the spread 
of undesirable brush and weeds, (2) the increase of needlegrass and 
other largely unpalatable grasses, and (3) serious erosion. An abun- 
dance of prairie chickens cannot be maintained on overgrazed tracts ; 
it is equally impossible to maintain forage and soil on such areas. 

Oil Development 

Oil development, which began with the discovery of the Spindle 
Top field in Jefferson County in 1901, has extended to every county 
in the coastal section. All the Attwater's prairie chicken area is 
classed as potential oil land, and almost every acre has been surveyed 
not once, but several times by oil crews. Veritable forests of oil der- 
ricks now stand in areas that once provided some of the finest prairie 
chicken range. In these areas, as in Fort Bend County, prairie 
chickens are almost, if not completely gone. 

Dkainagh 

Drainage canals, as in Brazoria and certain other coastal counties, 
have in some instances improved the territory within a mile or so of 
their margins by providing a permanent water supply where it was 
otherwise lacking during the summer months. On the other hand, 
drainage canals have doubtless decreased the general wildlife pro- 
ductivity of the counties in which they are situated by speeding up 
the run-off and thus lowering the water table. Until recently many 
prairie ponds retained water throughout the year, produced crappie, 
bream, and other edible fish, held safe nesting cover for black 
mallards and other water birds, grew an abundant supply of food for 
wintering waterfowl, and served as concentration points for prairie 
chickens during the heat of summer. Now they go dry during the 
slightest drought and produce virtually nothing. 

PASTtTRE Mowing 

Regular mowing of grassy areas, mainly for hay or increased 
forage production, has promoted a nearly pure stand of grass in some 
of the areas treated and has reduced shade and food, and the general 
attractiveness of the areas for prairie chickens and certain other 
valuable wildlife. In Colorado County, areas that have been mowed 
regularly for long periods are virtually game deserts; prairie chickens 
use them little even at nesting time. Pasture mowing in coastal 
Texas appears to be extending rapidly, and further reduction in 
wildlife resources may be expected from this cause unless definite 

303807°— 41 4 



44 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

modifications are effected. Fortunately, the detrimental effects of 
pasture mowing to upland game birds may be mitigated, at least to 
some extent, by following management recommendations listed on 
page 66. 

Mechanical Accidents 

Prairie chickens sometimes fly into telephone wires, fences, and 
houses, or are struck by automobiles. In six instances in 1937 birds 
were noted as accidentally killed in the Eagle Lake section — as many 
as were recorded for predation. Mortality from accidents may be 
far more serious than is generally appreciated. 

Hunting 

Last, but not least, hunters certainly have contributed to prairie 
chicken decrease. Hunting has never been well regulated, and laws 
governing the taking of the birds have always been inadequate. Ac- 
cording to the Texas Game, Fish, and Oyster Commission (Ann. 
Kept., 1929: 86-91) prairie chickens had no legal protection until 
1883, when a 5-month closed season was declared during the breeding 
period. In 1885, 148 counties claimed partial or total exemption to this 
and other regulations, and it was not until 1903 that the legislature 
passed a bill designating the months of November, December, and Jan- 
uary as the open season and setting a daily bag limit of 25. The legis- 
lation of 1908 was indeed a forward step, but there was no conserva- 
tion body to enforce the m.easure, local officers being depended on 
to carry out its provisions. The Game, Fish, and Oyster Commis- 
sion was not created mitil 1910, and for many years it was without 
adequate funds and personnel. As late as 1919 there were only 
6 salaried wardens in Texas endeavoring to carry out, as best they 
might, almost wholly inadequate regulations. The law restricting 
the open season on prairie chickens to 4 days, September 1 to Sep- 
tember 4, inclusive, and the bag limit to 10 a day or 10 a season, 
was not passed until 1929. In 1937 there were only 9 full-time 
wardens in all the Attwater's prairie chicken country, and they were 
charged with patrolling more than 8 million acres ! 

Development of the coastal territory, as farming, grazing, and 
the exploiting of oil, crowded prairie chickens into ever smaller 
areas, where they were more easily found and killed. The Hug- 
the-Coast Highway (State Highway No. 35) and various other roads 
increased patrol problems; the intercoastal canal in Galveston, Cham- 
bers, and Jefferson Counties made formerly remote areas easily 
accessible to poachers. The number of hunters increased as trans- 
portation facilities and weapons were improved. The open season in 
September, normally a dry period (see pp. 57 to 68), did much to 



ATTWATER'S PRAIRIE CHICKEN 45 

popularize hunting from automobiles. With these and other advan- 
tages, hmiters evidently harvested too closely. In the Bernard River 
country (western Austin County and northeastern Colorado Coimty), 
for example, it is known that in 1936 hunters killed 66 chickens, or 
22 percent of the estimated total population (300). This was accom- 
plished despite the fact that the gunners were closely supervised and 
did not hunt in the most densely populated pastures. It is probable 
that excessive kills have occurred in other areas for many years; 
the 1937 census showed that Attwater's prairie chickens were nearly 
or completely extirpated except on or adjoining lands where they had 
been hunted little, if at all, for at least 10 years. In Harris, Galves- 
ton, Waller, and possibly in parts of other counties, hunting has 
probably been the agency most largely responsible for prairie chicken 
decline. 

MANAGEMENT 

Leopold (1931 : 3) has defined game management as the art of 
making land produce annual crops of wild game for recreational use. 
In coastal Texas, the management of prairie chickens must consist 
largely of the preservation of suitable grassland areas. Increased 
protection, habitat improvement, adequate predator control, and 
proper regulation of the harvest, hovvever, will greatly encourage 
recovery. 

PROTECTION 

An act (H. B. 30) passed by the State legislature, effective Sep- 
tember 24, 1937, forbade the killing of prairie chickens in Texas for 
a period of 5 years. This measure removes much of the pressure 
previously exerted on the birds during the regular open hunting sea- 
son, for true sportsmen will observe the decree. Landowners, game 
wardens, and other interested individuals, however, will remember 
that close seasons may tend to stimulate rather than retard the opera- 
tions of game bootleggers. According to the consensus of State 
game wardens in the coastal territory, violators are especially active 
(1) during the birds' spring courtship season when the conspicuous 
males, their instincts of self preservation dulled by the the mating 
urge, are easy targets for .22-caliber rifles; (2) late in July and 
August, when the tame young birds are of "frying" size; and (3) 
during the duck season, when whirring flocks of Attwater's prairie 
chickens evidently tempt gunners who have insufficient self control. 
Coastal game wardens report that, in years past, probably as many 
prairie chickens were illegally killed during the duck season as were 
taken legally during the then open season in September. The restora- 
tion of the species demands close protection for the remaining birds 
at all times. 



46 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

Although game wardens in the prairie chicken country are sin- 
cere and energetic, the territory is too vast for adequate protection 
under the facilities available. Sportsmen may render valuable aid 
by helping conservation officers apprehend irresponsible hunters, but 
landowners or their resident agents must handle the job if prairie 
chickens are to receive anything like adequate protection. Land- 
owners, individually or in groups, would do well to incorporate their 
holdings to form game-management areas, as advocated by the Ex- 
tension Service, Texas Agricultural and Mechanical College and the 
Texas, Game, Fish, and Oyster Commission. Under that plan, in- 
creased protection is provided through appropriate posting and 
provision by the landowners of qualified, resident, free-service State 
game wardens. Also technical service is given in solving predator 
problems, improving wildlife food and cover, properly regulating 
harvests, and otherwise maintaining wildlife crops. Nonresident 
owners should check up on the manner in which their foremen 
or lessees protect wildlife during their absence. It is regrettably 
true that some supposedly protected ranches are in reality hunting 
clubs for irresponsible agents and their friends when the landowners 
are away. Long-time lessees who wish to manage prairie chickens or 
other game should insist that their contract include control over the 
wildlife resources of the property as well as over grazing or other 
values. These lessees may thus avoid embarrassment from unwel- 
come hunter guests directed to the area by the absentee owners. 

Landowners who contemplate leasing their holdings for oil develop- 
ment might well follow the precedent set by a ranch owner in Refugio 
County. Each of his contracts carries the provision that the lease 
shall terminate immediately after any representative of the contract- 
ing company is caught on the property with a gun of any kind. 
Such a clause properly shifts the burden of supervising irresponsible 
oil workers from the landowner to the oil company. 

Increased protection of the few remaining Attwater's prairie 
chickens is necessary for success in management. Protection alone, 
however, is largely ineffective in areas where proper food and cover 
conditions are lacking. 

HABITAT IMPROVEMENT 

At present there are few areas in Texas where excellent conditions 
for prairie chickens prevail, and populations fluctuate markedly 
(table 15). Increase or decrease in study areas was thought fre- 
quently to coincide with fluctuations in the supplies of food, cover, 
or surface water. In many areas marked seasonal movements may 
be averted and larger and more stable populations maintained by 
removing deficiencies in habitat. 



ATTWATER'S PRAIRIE CHICKEN 



47 



Table 15. — Fluctuations in numbers of prairie chickens, Thomas and Koy pas- 
tures, Colorado County, 1937 





Size 


Prairie chickens found 


Pasture 


Feb. 
221 


Apr. 
13 


May 
2 


June 
2, 8, 10 


July 
26 


Sept. 
1 


Oct. 
22 


Nov. 
1 


Thomas 


Acres 
817 
460 


Num- 
ber 
31 



Num- 
ber 
30 



Num- 
ber 
28 



Num- 
ber 
37 16 
14 


Num- 
ber 

23 


Num- 
ber 
17 
32 


Num- 
ber 




Num- 
ber 
1 


Koy - ... .- 










1 Count of birds at or near the courtship grounds; no allowance made for any birds that may have been 
missed. All other counts were by the rope method. (See p. 49.) 

Evaluating Conditions 

In some instances it is relatively easy to point out one or more ways 
in which areas are inferior. Safe nesting cover is deficient in burned 
pastures that are devoid of old vegetation except in low damp places. 
Shade is insufficient on lands kept free of tall weeds or shrubs by 
mowing or grazing. Winter food, or cover, or both are usually lack- 
ing in areas having few native food-cover plants, as ragweed, 
goatweed (Croton), marsh-elder, or ruellia. Sometimes, however, 
habitat deficiencies are obscure and general observations of an infre- 
quent nature do not identify them. Accurate inventories are of 
assistance in determining (1) whether habitat improvement is needed, 
(2) what should be done, (3) results of work done, and (4) the sur- 
plus available for hunting. Management programs should be formu- 
lated on the basis of data obtained during inventories conducted 
thrice annually, in spring, summer, and winter. Inventory methods, 
recording and interpreting data, and management practices are dis- 
cussed in the following paragraphs. 

CBajsus Methods 



SPBING COUNT ON THE COURTSHIP GROUNDS 

The first census method that has been tried and found useful is 
the spring count of birds on the courtship grounds. Necessary are 
an automobile, preferably of light build and high clearance, a driver 
who is well acquainted with the area, and someone to act as observer, 
note keeper, and gate opener. 

A count is made on each courtship ground in the area, recording 
the number and sex of birds assembled there and the number and 
sex of birds seen between these grounds. The number of hens is 
recorded as a supplementary check. The number of males, increased 
80 to 110 percent to allow for females that will be missed is accepted 
as the total population of the census area. For best results, the 



48 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

spring count is made in March from daybreak to about 7 : 30 a. m. 
A population estimate based on the maximum count obtained by 
reworking the same area three successive mornings, or often enough 
to offset variations due to unfavorable weather, is likely to be suffi- 
ciently accurate. Where recounts are impracticable, the single enu- 
meration should be made on a clear, quiet morning after a brisk 
norther. 

Courtship grounds may be located by sight or sound of the birds 
assembled there, but it is preferable to "drive out" the census area in 
belts 150 yards or less wide. Drumming grounds should not be ap- 
proached more closely than is necessary, because flushing the birds 
leads to inaccurate counts. As birds frequently squat, or freeze, at 
the approach of a car, it is desirable to wait at each occupied booming 
ground and refrain from counting until after vigorous courtship ac- 
tivity has been resumed. It is good policy to encircle a counted area 
completely before proceeding to a new site, for the fresh car tracks 
often assist in avoiding duplication. 

The accuracy of spring counts on the courtship grounds was tested 
in the following ways: (1) A section (640 acres) was covered on 10 
successive mornings; (2) a 1,000-acre pasture was searched with the 
aid of 15 bird dogs; (3) a 1,000-acre pasture was recounted by 5 men 
using 2 cars, 3 horses, and 2 dogs ; (4) a section worked 3 successive 
days was rope counted. Spring counts have been made over ap- 
proximately 150,000 acres in Colorado, Wharton, and Austin Counties. 
These studies show that the enumeration of birds on the courtship 
grounds is the most rapid and economical of all known census tech- 
niques. More than 2,000 acres a morning have often been covered in 
areas having populations of about 1 bird per 45 acres. There are no 
indications that the method affects courtship activities adversely or 
that it greatly endangers early nesting. Also, the spring count of 
males is useful in yielding data on prairie chicken abundance in com- 
parable areas worked at nearly the same time and under nearly the 
same conditions. 

The spring count of birds on the courtship grounds, however, is 
not without its defects. Its accuracy is influenced by weather and 
other conditions at a time convenient for counting. Opportunity is 
limited to a few hours a day (from about 6 to 7 : 30 a. m.) over a short 
period (in March). The spring count does not reveal the number of 
females present, consequently, it does not produce reliable quantita- 
tive data on sex ratio and total population. Some observers experi- 
ence difficulty in distinguishing males from females, especially in the 
poor light of early morning. To them the analysis of sex differences, 
presented on p. 49, may be helpful. 



North American Fauna 57, Fish and Wildlife Service 



PLATE 13 




V«if 





B49329; B489:9 



Above, Rope counting uf prairie ctncl^ens on Matagorda Island, Tex., October 30, 
1937. Below, Rope counting in myrtle bru.sh; Liberty County, Tex., approxi- 
mately 8 miles southeast of Devers, June 27, 1937. (Photos by W. P. Taylor.) 



ATTWATERS PRAIRIE CHICKEN 



49 



FIELD BASIS FOR DIFFERENTIATION OF THE SEXES IN SPRING 

Basis Males Females 

General color Light gray Brownish gray. 

Color of breast Not perceptibly different Much lighter than that 

from that of back. of back; appears al- 
most white in flight. 

Barring on back and Heavj^ black, well defined. _ Light, brownish black, 

breast. poorly defined. 

Color of head Orange - colored comblike Orange -colored combs 

structure present above absent. 

each eye. 

Feathers of crest Seldom erect Frequently erect. 

Neck Appears thick and heavy, Appears thin and long; 

with large, brightly col- air sac and neck tufts 

ored (orange) air sac rudimentary {%& inch 

apparent on each side of long). 

neck under prominent 

(2.25 to 2.90 inches) neck 

tufts. 

Size Large, heavy (about 2}Ob.)- Small, light (about 1% 

lb.). 

Action on courtship Bold, struts, fights, and Shy, does not strut, fight, 

grounds. booms in open cover. or boom. 

Flocking Usually in groups of 8 to 12 Usuallj^ alone. 

when booming, feeding, 

or resting at midday. 

Flushing Laborious take-off; cackles Easy take-off; usually 

when rising from ground. does not cackle. 



THE BOPE COUNT 



A second method of counting, one that has been tested with most 
encouraging results in the coastal prairie chicken country, is the rope 
count (pi. 13). Essential equipment includes two automobiles, 
preferably of light build and high clearance, an inch rope or a 
quarter-inch flexible steel cable 60 to 120. yards in length, and two 
strong swivels. An extra supply of water for radiators is needed 
in hot weather as cars heat up under the heavy going. In addition 
to drivers for the two cars, a third person should be taken along, if 
possible, to act as note keeper and general handy man. 

When the census area is reached, one swivel is attached to the 
right end of the rear bumper of the car in which the note keeper 
is to ride, and the second swivel is attached to the left end of the 
rear bumper of the other machine. Each end of the rope or cable 
is then securely tied to a swivel. Care must be exercised to see that 
the rope or cable, in turning, will tighten its twist and not loosen or 
unravel. One machine takes position parallel to a fence or other 
definite landmark while the other goes far enough way to stretch the 
rope so that only a slight bend remains. After both cars are in 
position, they drive over parallel courses at a uniform speed of 5 



50 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

to 15 miles an hour, which may be increased in light cover but 
which should be reduced in heavy vegetation to keep the rope, for 
the greater part of its length, about 5 inches above ground. Birds 
are tabulated as they are flushed. Those flying into uncovered ter- 
ritory are deducted when that area is dragged. When the end of 
a strip is reached, the car in which the note keeper rides turns and 



J^ 



Belts. En<iHftr«-», 



Icftal 



I 



6elt4. 






Beit 3. 



Belil. 



(eSI 



ftope-»« 5tart Here » 2*=" '• 

s 



FiGtTEE 4. — ^Diagram of the rope count. Arrows show course of each car. 

retraces its course while the other car makes a wide swing to the 
outside margin of another belt (fig. 4). This is repeated until every 
part of the census area has been covered. 

The principle of rope counting is not new. Askins (1931: 8) re- 
ports that market hunters and others in Kansas "* * * hitched 
a wire between two wagons and with these driving across the prairie 
300 yards apart, the gunners walked behind the wire taking the 
grouse as they arose until the wagon was filled." Butchers of wild- 



ATTWATER'S PRAIRIE CHICKEN 51 

life (they have no claim to the title of sportsmen) have used modi- 
fications of this system in coastal Texas for years. 

The rope census method has been checked and rechecked for ac- 
curacy against the spring counts of birds on the drumming grounds, 
car counts, and counts with bird dogs. The rope count, by far the 
most efficient of all, has been tried over approximately 45,000 acres 
of grouse range, including every major prairie type in which Att- 
water's prairie chickens occur in Texas. Heavy myrtle brush, as 
in Jefferson, Liberty, and other counties east of the Brazos River, 
light to heavy Pasyahmv-Andro'pogon grassland as in Brazoria and 
Colorado Counties, live oak shinnery in the northern part of Vic- 
toria County, rough weedy hog wallow blackland of Eefugio County, 
and even the extremely rough salt-grass area of the same section, 
have all been negotiated successfully. These tests have demonstrated 
clearly the practicability of the rope coimt under all coastal prairie 
conditions. Another advantage is speed; a party can easily cover 
2,000 acres a day ; Waddell and the writer having counted the birds 
on an area of this size in one morning. 

Ropes last for a considerable period, one that has been dragged 
over 20,000 acres still being used. This method of counting is not 
closely limited to a short season, or to a particular part of the day, 
as is the spring count on the courtship grounds. The accuracy of 
the rope count is not dependent on special weather conditions or on 
other variables over which man has no control, its major advantage 
lying in the fact that, when properly used, it gives an accurate 
quantitative count in the census area. For that reason, it is most 
useful in prairie chicken management. 

The rope count is dangerous for the layman to use during the 
nesting season and when young birds a.re small (during the latter 
part of March through June), for unless extreme care is taken, nests 
may be broken up and young birds injured, scattered, or even killed 
by a fast-moving, 1-inch rope. A i/4-inch rope, 50 yards long, how- 
ever, has been used with success in locating nests and broods without 
detriment to the birds. Coffee-bean plants, yaupon bushes, trees, 
and old fence posts are obstacles to rope counting, but they can be 
avoided without great loss of time, and, with care, few breaks in 
the rope or cable result. Of course, cultivated fields cannot be 
traversed without injury to standing crops, and counting is difficult 
and sometimes impossible in fallow rice fields where levees are high. 
Inexperienced persons sometimes have trouble in keeping the proper 
amount of slack in the rope and in following the car tracks which 
are depended upon to mark the inside margin of every new belt. 
These minor difficulties, however, are rapidly overcome by practice. 



52 NORTE AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

CAH-DOG COUNT 

A car-dog count is made by driving out an area in belts 40 to 
150 yards wide and releasing dogs to work the area where birds are 
known or strongly suspected to be. Necessary equipment consists of 
one car and one well-trained dog, but two cars, with a man and two 
dogs in each, speed up the work more than 100 percent. 

Since 1936 this method has been employed in working over 25,000 
acres. It is economical and is highly enjoyable to dog lovers, but 
it is slow. The work of different dogs and that of the same dog at 
different times and under different conditions varies greatly. Dup- 
lications in counts or recounts are virtually unavoidable on well- 
populated range, and misses are frequent. As reliable data are diffi- 
cult to obtain by this method, it should be used only when other census 
techniques are impossible. 

Using the Census 

Censuses produce the most dependable information when applied 
over an entire management area. Wliere this is impracticable and 
sampling is resorted to, care must be taken to insure that the selected 
area is typical with respect to vegetation, topography, water, and the 
like, and is sufficiently large. In a pasture consisting of 60 percent 
flat grassland with little or no brush and 40 percent sandhills covered 
with live oak shinnery it would be incorrect to sample only the sand- 
hill territory and apply the findings to the flat grassland as well. 
Sampling should be divided proportionately between distinct environ- 
mental types. Sample areas should be at least a section, or 640 acres, 
in size, and they should preferably cover 2,000 acres. Thoroughness 
should never be sacrificed for extent of coverage, however, as accurate 
censuses made thrice annually on a well-chosen section over a period 
of several years will yield infinitely more usable data than will hap- 
hazard counts sporadically undertaken over more territory than can 
be conveniently handled. 

During the spring census, investigators should list (1) males, (2) 
females, (3) occupied courtship grounds and the number of males at 
each, (4) unoccupied courtship grounds, and (5) jack rabbits, in areas 
where they are a common resident species, as in the country west of the 
Brazos River. Census sheets should show also (1) name of the pasture, 
(2) name of owner, (3) size of sample area, (4) exact location, (5) 
date of census, (6) counting method used, (7) weather, and (8) names 
of the investigators. Additional notes taken should describe (1) the 
type of country censused, whether flat grassland with few weeds, 
rolling country with scattered myrtle bushes, and so on ; (2) grazing 
pressure, whether light, medium, or heavy; and (3) recent burns on 
high or low ground, showing the percentage of area burned, whether 



ATTWATER'S PRAIRIE CHICKEN 53 

burn is general or spotty, and the location of unburned cover. Care- 
ful compilation of data greatly facilities accurate interpretation. 

If prairie chickens are numerous in the sample area, 1 to every 
10 acres or less, cover conditions should not be changed. Instead, 
steps should be taken to insure that grazing and burning practices 
will duplicate the conditions in future years. If the birds are scarce, 
less than 1 to every 10 acres, and if they have not been overshot, habitat 
deficiencies should be sought and corrected. 

SPRING 

Probable habitat deficiencies limiting prairie chicken numbers in 
spring are scanty, poorly distributed, or overdense nesting cover 
and a shortage of suitable courtship grounds. Common causes 
of deficient cover are general burnmg and overgrazing that result in 
scarcity or complete absence over more than 60 percent of the area 
of old vegetation, left from previous years at an average height of 
at least 5 inches, and poorly distributed cover confined to a particular 
part of a pasture or to low, poorly drained situations. Undergrazing 
is the usual cause of overdense cover, the thick matted vegetation that 
chickens regularly avoid. Where jack rabbits (Taylor, Vorhies, and 
Lister, 1935) are a common resident species, they are usually either 
very numerous, 1 to every 10 acres or less, or entirely absent where 
cover is too scanty or too poorly distributed to be suitable for nesting 
prairie chickens. Jack rabbits are frequently scarce, 1 to every 80 
acres or more, however, in cover that is overdense. A markedly un- 
balanced sex ratio, with more than twice as many male prairie 
chickens as hens, also has been noted in pastures where nesting cover 
was deficient. 

In areas in which the cover is scarce because of general burning, 
conditions are improved by leaving 40 percent or more of the grassy 
cover unburned each year. Unburned cover should be well distributed 
over the pasture, the gi'eater part being on the highest, best-drained 
ground, in j^atches of 5 to 40 acres. Favorable conditions are en- 
couraged if burning is carried on when there is little or no wind and 
the vegetation is slightly damp. A quiet day following a light shower, 
or a still night after the dew has begun to fall, is preferable. A test 
fire should be set in a protected corner of the pasture. If it burns 
slowly, consuming only the most combustible material, and dies down 
in 5 to 15 minutes, a series of fires then may be set throughout the 
pasture. The number should be strictly regulated by the acreage to 
be burned and the manpower available to curb the fires in case of such 
unforeseen difficulties as a fresh breeze that may put fires out of con- 
trol. The best insurance against trouble from that cause is a plowed 
fire lane, 5 to 10 feet wide, completely encircling the pasture and 



54 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

dividing it into blocks of approximately 100 acres each. All pasture 
burning should be completed by December or early in January, well 
in advance of the nesting season. 

Moderation in grazing is important. Cattle should not be left to 
graze on a tract until unpalatable bunch grasses, as smut grass, salt 
grass, big bluestem, and tlie like, are all that remain. Ideal condi- 
tions are approached when the number of animal units is strictly regu- 
lated according to the quantity and quality of the available forage. 
This practice avoids a condition of cover that is scanty in dry years 
and overdense in wet years, and, besides being favorable to prairie 
chickens, it conserves the soil and the range. 

A shortage of courtship grounds, short-grass areas from one-half to 
10 acres in extent surrounded by light to medium-heavy grassy cover, is 
frequently indicated by an unbalanced sex ratio with more than twice 
as many females as males or by a preponderant male population of 8 
to 15 or more birds on each booming ground. Common causes of in- 
adequate courtship facilities are (1) a lack of hardpan flats; (2) 
general burning, which denudes vegetation over a wide area and causes 
prairie chickens to leave ; and (3) undergrazing, resulting in tall cover 
even on hardpan areas. These deficiencies, however, are remedied by 
spot burning and moderate grazing. 

StTMMEB 

Probable deficiencies that limit the number of birds in summer are 
an insufficient supply of water in dry years and inadequate shade. A 
count made from July 1 through August 10, preferably over the same 
area covered in spring, reveals the number of yomig produced, and 
thus serves as a check on the success or failure of the breeding season. 

The data recorded for the summer count should be the same as for 
the spring count and, also, investigators should note (1) the number 
of young, (2) the number, character, and location of water supplies, 
and (3) distribution of birds with i-espect to water and weedy cover. 

A larger population of adult prairie chickens than was found in 
spring shows either that the spring census was inaccurate, or that 
other birds have moved in. In the latter event no habitat manipula- 
tion should be attempted unless the resident population plus the in- 
flux averages less than 1 bird for every 10 acres, and a larger popula- 
tion is desired. If the adult population has decreased since spring, 
however, and it is established that poaching has not occurred, the 
census data should be examined for information suggesting causes 
of the decline. 

Indications of deficient water are the absence of watering places a 
mile or less apart, and the concentration of birds and jack rabbits in 
parts of the area where water is available. Indications of deficient 



ATTWATER'S PRAIRIE CHICKEN 55 

shade are the scarcity of prairie chickens and jack rabbits where sur- 
face water obtains. Ordinary causes of insufficient water are drainage 
and unusually dry seasons. Water supplies can be improved by clean- 
ing and deepening natural ponds or constructing new ones, and allow- 
ing windmill pumps to spill over and maintain puddles nearby. 

Common causes of inferior shade are heavy grazing and mowing. 
Shade deficiencies usually can be corrected naturally by moderate 
grazing and leaving unmowed plots 1 to 10 acres in extent in flats 
near ponds. Other methods of obtaining and maintaining tall shading 
cover are by (1) fencing tracts from i^ to 10 acres in size within 100 
yards of water holes and leaving the fenced areas ungrazed ; (2) plant- 
ing tamarisk, chinaberry, black locust, elm, sycamore, cottonwood, or 
other adapted trees near water supplies; (3) constructing two or more 
brush racks 5 by 6 by 2 feet high on knolls on high ground near 
ponds ; and (4) strip plowing near ponds as outlined on page 56. 

An increase of 100 percent in the number of prairie chickens in any 
year is excellent. An increase of 50 percent or less may indicate 
either a poor breeding season or abnormally high predation. Eainf all 
records for May show whether breeding conditions are poor; in the 
event heavy rainfall is not the causative agent, predators may be 
responsible. In the latter instance, the niunber of predatory dogs 
and house cats should be reduced by shooting or trapping. If a thor- 
ough job is done and yet the increase is small, the aid of State or 
Federal wildlife technicians should be solicited. 

WINTEE 

In winter, a grouse habitat may be deficient in food, cover, or both. 
This may best be determined by study of information obtained during 
a December or early January reconnaissance of territory that was 
covered in summer. Except for the data on the number of young 
birds and on the water supply, information, recorded in winter should 
be the same as that in summer, and it should show whether birds are 
generally distributed or heavily concentrated in small areas. The rope 
count is the preferred method of winter census, dog counts being made 
only when rope counting is impracticable. 

Assuming that poaching is not a factor, a winter population larger 
than that of the summer, shows habitat conditions on a census area 
already more favorable than those in pastures nearby and suggests that 
management be directed at maintenance, rather than at alteration of 
environment. A winter population smaller than that of the summer 
suggests food or cover deficiencies. Other indicators of such inad- 
equacies, generally occurring together in heavily grazed areas, are a 
prevalence of largely unpalatable plants, as goatweed, marsh-elder, 
dogfennel, perennial ragweed, smutgrass {SporohohiS poiretii), and 



56 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

cordgrass; a concentration of prairie chickens in small parts of the 
area; and an abundance of jack rabbits (averaging 1 to every 10 acres 
or less) 5 or their complete absence. Indications that food only is lack- 
ing are a uniform growth of heavily matted grass, a sparse growth 
of weeds, and a scarcity of jack rabbits (averaging 1 to every 80 acres 
or more). Moderate grazing encourages favorable food and cover 
conditions. 

To make up for local shortcomings, prairie chicken managers may 
establish (1) stockproof -fenced areas of i/^ to 10 acres in as large num- 
bers as practicable; (2) plowed strips 20 to 50 feet wide dividing 
sparsely inhabited parts of pastures into blocks of 50 to 200 acres ; and 
(3) unmowed patches of cover of 2 to 10 acres or more, situated not 
more than 300 yards apart. Fenced areas should not be grazed, and, 
if possible, half of each fenced area should be planted annually to 
Schrock, German millet, dwarf milo, hegari (pi. 14) , or red-top cane. 
Brush racks built in the corners of fenced areas attract quails as well 
as prairie chickens. In average years strip plowing may be done 
with satisfactory results from December through April, but February 
is considered most favorable. The best effects on experimental areas 
in Wliarton County and at College Station have been obtained on 
strips that were plowed shortly before or after a rain and harrowed 
immediately after the preliminary breaking. Unmowed patches of 
cover should be left on knolls or ridges, in flats around ponds, or in 
other places where sizable stands of weeds occur. 

General Recommenditions for Habitat Conteoi. 

Landowners who do not undertake intensive management of prairie 
chickens based on counts made three times a year may adopt any 
or all of the following general recommendations with the assurance 
that some improvement will result: 

Pastures should be grazed moderately by livestock. 

Pasture burning should be completed before February 1; in excess of 40 
percent of the pasture should be left unburned, with the remaining 
cover well distributed in patches of 5 to 40 acres on the best drained 
areas. 

Mowing should not be done before July 1 ; unmowed patches of 2 to 5 
acres or more, not more than 300 yards apart should be left on flats, 
knolls, or in other places where there is a good stand of weeds. 

In summer windmill pumps should be allowed to form puddles. 

Px-edatory house cats and dogs should be rigidly controlled. 

The present 5-year close season (efCeetive September 1937) should be 
enforced. If and when the season is reopened, not more than 35 percent 
of the known population should be shot when rainfall in May is normal 
or less. In years when rainfall in May is approximately twice normal, 
no birds should be killed. 



North American Fauna 57. Fish and Wildlife Service 



PLATE 14 




ATTWATER'S PRAIRIE CHICKEN 57 

PREDATOR CONTROL 

Exhaustive studies by McAtee (1931, 1932, 1935, 1936), McAtee and 
Stoddard (1930), Fisher (1893)), May (1935), and others have dem- 
onstrated rather conclusively that the food of most flesh-eating birds 
and mammals is determined mainly by the availability of prey. 
Errington (1935) adds that predation is largely confined to in- 
secure or surplus populations; in areas where there is adequate 
food and cover, hawks, owls, skunks, opossums, and the like feed 
principally on the more common rats, mice, snakes, frogs, and insects, 
rather than on the less numerous, swift, and elusive game birds. 
Flesh eaters often are neutral, and may be actually beneficial, in 
relation to sport and agriculture. Specific data presented on the 
relationships of Attwater's prairie chicken and its natural enemies 
(pp. 37 to 40) are by no means so comprehensive as desired. The 
information at hand, however, apparently justifies the following 
general recommendations concerning predator control on prairie 
chicken range: 

Feral house cats and predatory dogs may well be controlled. 

Hawks, owls, and fur animals should not be killed indiscriminately, their 
control being limited to known offenders. Inhumane pole traps should 
not be used. (All raptorial birds except Cooper's, sharp-shinned, and duck 
hawks, goshawks, and great horned owls are protected in Texas.) 

Fur animals should be taken only during open seasons when furs are prime, 
and the harvest should be regulated to promote sustained yields. 

HARVESTING THE SURPLUS 

Former laws governing the shooting of Attwater's prairie chickens 
left much to be desired. Regulations in efiect from 1925 through 
1937, providing an open season from September 1 through September 
4 and a bag limit of 10 birds a day or 10 a season, actually stimulated 
butchery and injured sport. Hunting was allowed when birds were 
easily found, many being concentrated near patches of heavy cover 
near surface water. Unwary j^oung of the year were easily shot be- 
cause they flushed near the gunner, flew straight and slowly for short 
distances, and ran but little after alighting. Adults performed sim- 
ilarly, probably because the weather was warm, the cover dense, and 
because they were in molt. September heat prohibited efficient work 
by bird dogs, so crippling losses were doubtless high. As it was 
also uncomfortably warm for men to walk, hunting by cars, and 
shooting from them, in violation of State law, became the rule in 
Colorado and Austin Counties and probably elsewhere in coastal 
Texas. 

In the future, the power of making regulations might well be 
delegated, under proper safeguards, to the State Game, Fish, and 
Oyster Commission, which has the benefit of information and counsel 



58 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

from its own trained game protectors and from experienced sports- 
men, as well as from wildlife specialists connected with the State and 
Federal Governments. This power should allow for prompt modi- 
fication of regulations in response to emergencies of climate, or other 
conditions affecting the welfare of the birds. The proper open sea- 
son on Attwater's prairie chickens, assuming that the nmnbers of 
the birds can be built up to withstand the drain of shooting, cannot 
always be determined in advance, and regulations should be formu- 
lated in accordance with local conditions as they develop. The State 
legislature, meeting only at 2-year intervals, must rely on the State 
Game Commission for appropriate regulation of the take of game; 
and only under that arrangement can the people properly hold the 
Commission fully responsible for game protection. 

If hunting is again allowed, geasons should not in any case open 
prior to November 15. Weather late in November ijs usually suffi- 
ciently cool for the comfort of men and dogs, and, normally, the 
prairies are too wet to allow hunting from cars. The prairie chickens, 
already congregating in winter packs, are widely distributed and 
strong flying; consequently, they are hard to find and even more 
difficult to hit. Probably because the young of the year are strong 
and more worldly wise, and because the weather is cool and the 
ground cover reduced, late fall birds regularly flush widely, twist 
crazily, fly swiftly and far, usually for a mile or more, and run after 
alighting. In other words the Attwater'g prairie chicken in Novem- 
ber is a game bird of the highest order; hunting it thoroughly tests 
the most skillful hunter and the best bird dog. That is as it should 
be in true sport. 

RESTOCKING 

At present the possibility that prairie chickens may be restored 
by artificial planting is remote, as wild birds are not available 
for trapping and moving, and artificial propagation has shown little 
promise. Furthermore, there is no assurance that priarie chickens, 
if available, would survive if moved. In Texas and Oklahoma, at- 
tempts to transplant lesser prairie chickens have been unsuccessful. 
Bent (1932: 263) records the failure of numerous attempts to trans- 
plant the greater prairie chicken in northern States. A number of 
these birds introduced in the vicinity of the Sault Sainte Marie and 
McMillan in northern Michigan persisted for a few years, but F. F. 
Tubbs, Michigan Department of Conservation, writes that they have 
disappeared. It is true that no intensive efforts have been made to 
transplant Attwater's prairie chickens in southern Texas, but there 
is no reason to believe that they would survive the process better 
than have their relatives. 



ATTWATER'S PRAIRIE CHICKEN 59 

Natural restocking, however, takeg place rapidly and efficiently 
when prairie chickens are properly protected and allowed to increase. 
Since 1935 practically all suitable territory in Refugio County has 
been restocked by natural spread from the Salt Creek Ranch and 
the properties of Martin O'Conner. When the birds are permitted to 
increase elsewhere, similar results may be expected. 

SUMMARY 

Attwater's prairie chicken, a characteristic bird of the coastal 
prairie, is one of three kinds that once occurred in Texas. A few 
lesser prairie chickens, smaller and paler in color than Attwater's 
subspecies, still persist in parts of the Texas Panhandle. The greater 
prairie chicken, however, has been entirely extirpated from its former 
habitat in the central and northern parts of the State. 

An intensive census made in the summer of 1937 revealed that 
only about 8,000 to 9,000 Attwater's prairie chickens then remained 
in Texas, approximately half of them being in Refugio County. 
The birds now inhabit only about 450,000 acres, compared with the 
more than 6,000,000 formerly occupied. The numbers of the coastal 
prairie chicken have declined 99 percent, and its range has decreasd 
more than 93 percent during the past century. 

The mating season begins late in January or early in February, 
when the males assemble on short-gi-ass areas early in the morning 
and late in the afternoon and boom and otherwise display the mating 
urge. Females are attracted to the courtship areas by this activity, 
and mating usually takes place there. Prairie chickens are pro- 
miscuous. The booming is at a climax in March and ends late in May. 

Nests containing eggs have been found from February 25 through 
June 17. The peak of the laying period, however, is late in March 
and in April. Females build their nests in dry vegetation of the 
previous year preferred nesting sites being in good cover in well-drained 
areas and within 5 yards of an opening. 

The normal rate of laying is 1 egg a day until the average clutch 
of 12 is completed, but intervals of 1, 2, and even 3 days are not 
infrequent. Subsequent attempts to nest may be made if earlier 
nestings are terminated while booming is still in progress. Second 
and third nests apparently are made in close proximity to those previ- 
ously destroyed, which probably jeopardizes their chances for suc- 
cessful termination. The mcubation period is 23 to 24 days and 
hatching occupies about 2 days more. The peak of the hatching sea- 
son is in May. Fertility of the eggs evidently is high. Nest losses 
in 1937, however, were 70 percent of 13 nests studied, and those in 
1938 amounted to 67 percent of 6 nests. 

303807° — 41 5 



60 NORTH AMERICAN FAUNA 5 7, FISH AND WILDLIFE SERVICE 

In 1937, of broods on which accurate counts were obtained, 48 
averaged 5.48 birds each. Mortality of young prairie chickens is 
highest (about 50 percent) in the first 4 weeks after hatching and 
comparatively low (about 12 percent) thereafter, a large share of the 
early mortality being in lost chicks. Other known causes of juvenile 
mortality include heavy or persistent rains during the brooding, 
drowning in rice fields, and depredations by natural enemies. Fam- 
ily disintegration, although gradual, begins when the chicks are 6 
to 8 weeks old. It is completed after cold northers late in October 
and in November induce fall flocking, or segregation of the birds 
into flocks according to sex. 

Unstable and temporary groups of 5 to 15 birds are common from 
September through early October, but singles, pairs, and trios pre- 
dominate at that season. As fall passes into winter, flocks become 
larger, and in December and January groups containing 35 to 800 
individuals have been observed. Singles, pairs, and trios, however, 
may be found throughout the year. 

Young prairie chickens evidently spend their first 3 weeks within 
half a mile of the spot where hatched. Late in May and in June, 
both young and adults move to territory where cover providing good 
shade is found within half a mile of surface water, there to remain 
usually until September. When fall rains and cool weather come 
and the fall weeds mature, the birds scatter widely, often becoming 
common where scarce or entirely absent at other seasons. Concen- 
tration into areas where there is moderate-to-heavy cover and ade- 
quate food is evident by November, and populations in favorable 
areas fluctuate little from then through spring. 

The food of adult prairie chickens is about 85 percent vegetable 
matter and 15 percent animal. With j'^oung birds the ratio of vege- 
table to animal is approximately reversed. Favorite sources of plant 
food are ruellia, perennial ragweed, blackberry, doveweed, and sensi- 
tive briar. Leading animal foods are grasshoppers and beetles. 
Greens (leaves, flowers, buds) are lowest in the diet in November 
and December; seeds are taken in the smallest proportions in Jan- 
uary, February, and March. Insects are least frequently captured 
in November, December, and January. 

Important factors limiting prairie chicken abundance include ex- 
cessive or persistent rainfall during the nesting season, heavy graz- 
ing, excessive pasture burning, agricultural operations, and over- 
shooting. Other destructive factors, not generally serious but some- 
times locally disastrous, include oil development, drainage, floods, 
drought, hurricanes, hail, the spread of woody vegetation into prairie 
land, predation, pasture mowing, and possibly disease. 



ATTWATERS PRAIRIE CHICKEN 61 

Available records from 1925 through 1937 show a positive correla- 
tion on unmanaged land between the production of young prairie 
chickens and rainfall in May. Good crops of young chickens are 
brought off in years when the rainfall in May is 1% inches or more 
below normal. Fair broods are produced when precipitation in May 
is nearly, or only slightly above, normal, while poor crops are probable 
when rainfall in May is about twice normal. If the findings in 
Colorado County apply to other parts of the coastal country, 2 years 
in 5, on the average, are favorable to prairie chicken reproduction, 
2 are fair, and 1 is poor. Conditions affecting reproduction are never 
the same for the entire range, for a county, or even for different parts 
of the same county, because of the scattered character of local rains. 
Attwater's prairie chicken is a highly fluctuating subspecies, its 
scarcity or abundance depending to a large extent on the precipita- 
tion in May. 

The annual kill of these birds cannot be intelligently regulated by 
such general open seasons and general bag limits as have applied 
in Texas in the past, but should be set, when permissible at all, by 
regulation by the State Conservation Department on the basis of the 
latest detailed information obtainable. 

Optimum prairie chicken range apparently consists of well-drained 
grassland supporting some weeds or shrubs as well as grasses, the 
cover varying in density from light to heavy; and with supplies of 
surface water available in summer. In short, diversification within 
the grassland type is essential. 

Management usually will involve protection against excessive kill- 
ing, improvement of food and cover, moderate control of predators, 
and wise regulation of the harvest. Responsibility for management 
must be assumed by the landowner. Food and cover deficiencies 
can best be recognized and their improvement and maintenance as- 
sured by careful counts of the birds on part, or all, of the managed 
area at three critical periods in March, July, and December. 

To obtain and maintain favorable food and cover, the following 
general practices are recommended: (1) Moderate grazing of pas- 
tures; (2) completing all necessary pasture burning before February 
1 and leaving unburned not less than 40 percent of the best drained 
ground; (3) mowing pastures after July 1 and preserving the native 
cover on knolls, around ponds, and m flats; (4) allowing wind- 
mill tanks to spill over in summer to increase the supply of surface 
water; (5) controlling the numbers of feral house cats and predatory 
dogs; and (6) allowing the shooting of not more than 35 percent 
of the known prairie chicken population in any year when rainfall 
in May is normal or below and prohibiting killing when rainfall in 
May is approximately twice normal or above. Hunting seasons 
should not open before November 15. 



62 NORTH AMERICAN FAUNA 57, FISH AND WILDLIFE SERVICE 

Under normal conditions hawks, owls, and fur animals do not 
appear to be serious predators on Attwater's prairie chickens, and 
should not be killed indiscriminately. 

Persons should not request the Government to furnish prairie 
chickens for r^tocking, because there is no surplus for the purpose 
and no evidence that the birds can be successfully transplanted. 

In the absence of ample reservations for the species all other 
favorable factors together cannot be counted on to save the bird 
from extinction. Before too late a large tract or tracts of suitable 
range should be established as a prairie chicken refuge by the Federal 
or State Government. 

LITERATURE CITED 

AsKiNs, Charles C. 

1931. Game bird shooting. 312 pp., illiis. New York. 
Bailey, Florence Mekriam. 

1927. Handbook of birds of the western United States. Ed. 10, rev., 590 pp. 
illus. Boston and New York. 
Bailey, Veenon. 

1905. Biological survey of Texas. U. S. Biol. Survey North Amer. Fauna 
25. 222 pp., iUus. 
Bbnotbe, Chables Emil. 

1892. Life histories of North American birds with special reference to 

their breeding habits and eggs, with twelve lithographic plates. 
U. S. Nat. Mus. Special Bull. 1, 446 pp. 
1894. Ti/mpanuchus americanus attwateri Bendire. Attwater's or southern 
prairie hen. Auk 11: 130-132. 
Bent, Abthue Cleveland, 

1932. Life histories of North American gallinaceous birds. V. S. Nat. Mus. 

Bull. 162, 490 pp., illus. 
Bbay, William L. 

1901. The ecological relations of the vegetation of western Texas. Bot. 
Gaz. 32:9^123, 195-217, 262-291, illus. 
Eekington, Paul Lesthb. 

1935. Overpopulation and predation : A research field of singular promise. 
Condor 37: 230-232. 
FiSHEB, Albert Kenrick. 

1893. The hawks and owls of the United States in their relation to agri- 

culture. U. S. Dept. Agr. Biol. Survey (Orn. and Mamm.) Bull. 
3, 210 pp., illus. 
Gross, Alfred Otto. 

1930a. The Wisconsin prairie chicken investigation. Amer. Game 19: 39-40, 

50. 
1930b. Progress report of the Wisconsin prairie chicken investigation. Wis- 
consin Conserv. Comn. 112 pp., illus. Madison, Wis. 
Leopold, Aldo. 

1931. Report on a game survey of the North Central States. 299 pp., illus. 
Madison, Wis. 

1933. Game management. 481 pp., illus. New York and London. 
May, John Bichabd. 

1935. The hawks of North America. 140 pp., illus. Nat. Audubon Soc, 
New York. 



ATTWATERS PRAIRIE CHICKEN 63 

McAtee, Waido Lee. 

1931. A little essay on vermin. Bird-Lore 33 : 381-384. 

1932. Confusions of an economic ornithologist. Bird-Lore 34 : 315-321. 

1935. Food habits of common hawks. U. S. Dept. Agri. Circ. 370, 36 pp., 

illus. 

1936. The Malthusian principle in nature. Sci. Monthly 42 : 444-456. 
and Stoddard, Hhbbebt Lee. 

1930. American raptores and the study of their economic status. Condor 

32: 15-19. 
Merrill, James Gushing. 

1879. Notes on the ornithology of southern Texas, being a list of birds 
observed in the vicinity of Fort Brown, Texas, from February, 1876, 
to June, 1878. U. S. Nat. Mus. Proc. 1: 118-173, 1878. 
Obebholsite, Haket Church. 

1938. The bird life of Louisiana. 834 pp., illus. New Orleans. 
Simmons, George Finlat. 

1925. Birds of the Austin region. 387 pp., illus. Univ. Texas, Austin. 
Stbeckee, John Kern. 

1927. Notes on the ornithology of McLennan County, Texas. Baylor Univ. 
Mus. Spec. Bull. 1, 65 pp. 
Stoddard, Herbert Lee. 

1931. The bobwhite quail: its habits, preservation, and increase. 559 pp., 

illus. New York. 
Tatlor, Walter Penn. 

1934. Significance of extreme or intermittent conditions in distribution of 

species and management of natural resources, with a restatement 
of Liebig's law of minimum. Ecology 15 : 374-379. 
VoRHiES, Charles Taylor; and Lister, Paul B. 

1935. The relation of jack rabbits to gi-azing in southern Arizona. Jour. 

Forestry 33 : 490-498, illus. 
Texas Game, Fish, and Oyster Commission. 

1929. Grouse or prairie chicken. Ann. Rpt. 1929: 86-91, illus. Austin, Tex. 
Tharp, Benjamin Carroll. 

1926. Structure of Texas vegetation east of the 98th meridian. Univ. Texas 

Bull. 2606, 100 pp., illus. Austin, Tex. 



INDEX 



Abundance, 6, 7. 
Agricultural factors, 40. 
americanus, Tympanuchus, 4. 
attwateri, Tympanuchus cupido, 1. 

Brood size, 18. 

Call, 12. 

Cat, house, 38, 39, 40. 

Census methods, 47. 

Coloration, 4, 5, 6. 

Courtship, 10. 

cupido, Tympanuchus, 1. 

Development of young, 16. 
Disease, 36. 

Disintegration, family, 19. 
Distribution, 2, (map) 3, 7. 
Drainage, effect of, 43. 

Eagle, bald, 39. 

Flocking, 20. 
Floods, 35. 
Food, 25. 

Goshawk, 39. 

Grouse, 39. 

Growth of young, 16. 

Habitat, 30. 

control, recommendations, 56. 

improvement, 46. 

requirements, 30. 
Hawk, duck, 39. 

ferruginous roughlegged, 39. 

Krider's, 39. 

marsh, 39. 

rough-legged, 39. 
Heath-hen, 1. 
Hunting, effects, 44. 

Increase, 20. 



Limiting factors, 31. 

Management, 45. 
Mating, 10. 
Mortality, juvenile, 19. 

Nesting, 14. 

Nests, predation on, 37. 

Overgrazing, effect of, 42. 

pallidicinctus, Tympanuchus, 4. 
Pasture burning, effect of, 41. 

mowing, 43. 
Population status, 8. 
Prairie chicken, Attwater's, 1. 

greater, 4. 

lesser, 4, 5. 
Predation, 37. 
Predator control, 57. 
Protection, 45. 

Quail, 39. 

Rainfall, 32. 
Restocking, 58. 

Seasonal movements, 21. 
Sparrow, English, 17. 
Starling, 17. 
Storms, 35, 36. 
Surplus, 57. 

Turkey, bronze, 17. 

Tympanuchus cupido americanus, 4. 

cupido attwateri, 1, 4. 

cupido cupido, 1. 

pallidicinctus, 4. 

Weight, 5. 
Wolf, red, 38. 
Woody vegetation, 36. 

Young, development of, 16. 
predation on, 38, 



o 



65 



10 



SEP